Add Save button to Edit Tags dialog

Add Save button to Edit Tags dialog

When editing an opening book it is very anoying if the Edit Book dialog closes
every time you add a move or change a weight, and closing the dialog was
(in WB) the only way to save the changes. A separate button now is added for
this. Pressing it will also cause a refresh of the list of book moves, so
the user can see if his change were accepted, and the consequences for the
playing percentages.