imitate other controls like DropDownButton, etc.
* rework several main toolbar items to use fox.form.Select instead of
other controls
* replace HOOK_HEADLINE_TOOLBAR_SELECT_MENU_ITEM with
HOOK_HEADLINE_TOOLBAR_SELECT_MENU_ITEM2 because of markup change (option
instead of menuitem)
* PluginHost: add some explicit typecasts to make intellephense shut up
This change introduces derived classes for ComboButton, DropDownButton
and Select that make sure that buttons do not remain focused after their
menus are closed. This allows using hotkeys after closing them.
Andrew Dolgov