Major refactoring of GenericPopUp

Major refactoring of GenericPopUp

Allow more transient dialogs in GenericPopUp
Remove grab from promotion popup
Fix other generic popup over transient popup
 To use the generic dialog generator for 'asynchronous' popups (Ask Qustion
 or Error popup caused by engine), the currentOptions setting has to be
 restored for the combo and checkbox callbacks of the transient to still
 work after the asynchronous dialog returns. Note that only transient dialogs
 can have check and combo controls.
Make generic calcel button suppressible
 Also #define some more symbols for Option.min flags,
 and move them to dialogs.h.
Change TypeInProc to general OK handler
 The move type-in now has its own option list, to distinguish it from
 the ICS input box, and give it its own OK handler. Rather than having
 the translation for <Enter> on the text widget call TypeInEvent directly,
 we let it call GenericCallback, which calls GenericReadout, which calls
 the OK proc, which does the job.
  To be able to call GenericCallback from the TypeInProc, the recognition
 of OK and cancel buttons had to be changed. This because it was too difficult
 to arrange the calling widget had label OK or cancell. So these buttons are
 no longer recognized by name, but by the option number passed as client data.
 (This solves the problem that a user could not make buttons named 'cancel'
 or 'OK'.)
Make Cancel button optional
Fix closing multiple popups of same kind
 The GenericCallback figures out its own shell, so all buttons of
 multiple dialogs keep working. External calls to PopDown only work
 on the lastcreated instance of that kind, though (including those from
 the Delete Window button, which can do 'cross-closing'). shellUp is now
 a counter, and PopDowns are only prevented when it reaches 0 or the
 current shell does not exist. (To know this, PopDown now resets shells[n]
 to NULL when is shell is destroyed.
  Beware of double PopDowns (through OK procs); they wreck the system.
Fix Delete Window button of multipe ErrorPopUps
 The action routine for handling the Delete Window now pays attention
 to the shell widget that the system passes to it, and temporarily
 replaces shells[n] by it to let PopDown act on the proper instance.
Add ListBox dialog type to GenericPopUp
Fix vert sizing of ListBox
Put listbox widgets in viewport
Put listbox in viewport
Improved xoptions.c support for focussing and listboxes
Fix OK-row button positioning
Let GenericPopUp take parent and modality as arguments
 This makes the code a bit more explicit and less kludgy. It also becomes
 possible to call the same dialog (e.g. Load Options) from the main menu
 and from another dialog (e.g. the Game List).
Support scroll function for generic popup listboxes
Fix scrolling
Move HighlightWithScroll to xoptions.c
Change scroll algorithm
Add mouse-wheel scroll to generic list boxes
Implement tabbing between text edits
Implement same-row text labels in generic dialog
Allow labels to specify their chaining in generic popup
 The opt.min variable is used to specify the chaining: 0xF0 are the bits
 for (left, right) chaining of the left side (0xC0) and right side (0x30).
 The 0xC bits determine top or bottom chaining of the entire label.
 Without anything spcified (0), the chaining is XtRubber.
 TextBox options can also specify top-chaining of their top. All this was
 needed to allow decent implementation of the Engine Output window with
 the generic popup. (Although tags and comment popup ca benefit from the
 latter feature.)
Let GenericPopUp support a Graph option
 The Graph option results in an area where one can draw something. It is
 positioned / chained similar to Label options. A handler for expose events
 can be specified in the textValue field of the option.
Implement box widgets and menu buttons in GenericPopup
 To enhance the capabilities of GenericPopUp such that it could create the
 main window, it needs to be able tha packaging of controls into a box widget
 (for mennu and button bar). Menu buttons are also required elements
 (although they do look a lot like comboboxes?) Option types BoxBegin and
 BoxEnd can now be used to bracket a group of controls that will be put
 in a box widget. (Cannot be used recursively!) The positioning of the box
 is similar to that of a Label, and is specified in the BogBegin option.
  The code to shrink the menu buttons to fit is also incorporated, to act
 on any box widget: if the BoxBegin option specifies a width, the elements
 in it are shrunk to meet the requirement. Otherwise the box just gets the
 size of the sum of its children (plus spacings).
  Label options can now specify a font, casted into their textValue field.
 (This is needed to get the proper size for the clock widgets.)
Implement callback in BoxEnd options
 BoxEnd is a pseudo-option, to trigger packing the preceeding ones in
 an earlier-opened box widget. In the process it calculates the size of
 the box widget (and trims it if a size was specified for it in the
 corresponding BoxBegin). The Option.target field of BoxEnd is now
 interpreted as a callback, which can be use to take decisions based
 on the determined size for the remaining options in the list, before
 these are processed b GenericPopUp.
Refactor xoptions.c
 Make a subroutine to set args shared by almost all widgets. Swap meaning
 of '1'-bit in option.min flag of Break option, to be consistent with
 SAME_ROW interpretation in other option types.
Make option tables consistent with refactored GenericPopUp
 The flag for stacking in the Break option needed to be inverted, and
 the BoardPopUp needed to pass the font in another field. Better use was
 made of the improved chaining options too.
Improve Graph-option event handling
 The user-supplied callback now gets 3 arguments passed: the event type
 (0 = pointer motion, 1...5 button press, -1...-5 release, 10 = expose),
 and two coordinates. For ouse events these are the pointer (x,y), while
 for expose events they are the window size (w,h). The callback is now
 specified in the option.target field of the Graph option.
Store engine options in malloc'ed memory
 The Option.name field has been re-declared as (char*),  from (char[MSG_SIZ]).
 There are still MSG_SIZ chars allocated irrespective of actual size, because
 the field is also supposed to store the textValue, which can be changed by
 the user. But at least it means that unused options of the generous list
 now don't waste much space. (And the prparated Option tables in dialogs.c
 will shrink by a large factor as well.)
Improve GenericPopUp ComboBox handling.
 The dialog type is now passed to the combobox callback as well, and this is
 used to really figure out what option it is called for.
Allow numeric comboboxes
 When no list of strings is given in Option.choice, the target is assumed
 to be (int), and the number of the slected entry is stored there. Also
 adapts the Label options that act as fillers to the new method for making
 dummies (namely NULL in the Option.name field).
Put comboCallback in Option struct
 Rather than having a general comboCallback variable for the entire current
 dialog, each ComboBox option can now specify its own callback in the
 target field of the option: the COMBO_CALLBACK bit of Option.min indicates
 whether the target is a variable to be set or a callback. The callback can
 still fetch the choice from the values array.
Allow generic CreateComboPopup also to do main menus
 An extra parameter to CreateComboPopup determines if the menu texts
 should be taken from a list of strings (the old method with engine-
 supplied choices), or from a menu table of MenuItems. It can now also
 recognize "----" as a menu break, and keeps margins (for the marking).
Make subroutine for determining curren combo selection
Various fixes to GenericPopUp
Delete one border-width setting
Fix max nr of args in GenerocPopUp
Fix button release events of Graph options
Fix generic Graph callback pointer motion coordinates
Make all format referencing in Option tables symbolic
Let Option.choice define menu texts, rather than Option.textValue
 This is more logical than ussing textValue for it, because choice already
 has the correct (char**) type, while textValue was (char*), and needed
 casting everywhere. Note that for engine options, the fields were the
 same anyway, so no back-end change was required. The textValue now
 contains the (casted) list of actual string values, where these are
 needed. (But for numeric and function menus they aren't.)
Add PopUp Option type
 An new pseudo-Option is defined, to add a popup menu to a previous Graph
 option. The actual popping up is done by the expose handler.
 The function XUngrabPointer is the key to success here. A PopUp option
 specifies a callback for handling the selection from the menu, which will
 be called with the option number, exacty as with ComboBox options.
Update option explanation in dialogs.h
Make Spin and CheckBox callbacks pass dialog number
 No longer rely on 'currentOptions' for getting the option belonging to
 the callback, but get it out of the dialogOptions array indexed by dialog
 type. This way things cannot be messed up by an asynchrounous error popup.
 It also means that it is now save for non-modal dialogs to use these options.
Use button widget for text behind checkbox
Let listboxes use general formatting hints
Let GenericPopUp option always finish last pane after Break
Allow LisBox to specify select callback in Option.textValue
Use double-click to trigger ListBox callback
Make ListBox callback re-entrant
Fix multi-line Label options
Separate CreateMenuItem out from CreateComboPopup
Chain checkbox texts entirely left
Allow a user-specified callback to Label options
 This is needed to implement the clocks. Let the CheckBox callback handle
 it. For now ther is no distinction between different mouse buttons.