Create General-Options dialog

Create General-Options dialog

The generic popup is used to implement a General-Options dialog, which
contains all Boolaen options that used to be set directly from the main
Options menu, plus a spin option for the flash count and flash rate.
The corresponing options are removed from the main Options menu, but the
whole thing is made conditional on a compiler switch OPTIONSDIALOG.
The dialog needs an OK callback for sending an altered ponder-state to
the engine. (Why isn't this option disabled in -ncp mode, btw?)
A spin control is added to adjust -animateSpeed between 5 and 100.
Add dropMenu and showTargetSquares item as well.