Fix bugs 1720 (almost) and 2877

Fix bugs 1720 (almost) and 2877

	* src/funcrequest.h: split UI enum into MENU and TOOLBAR

	* src/lyxfunc.C (getStatus): disable menu entries that need a
	buffer when window does not have focus (bug 1720)
	(dispatch, sendDispatchMessage): properly redraw toolbar after each
	action (bug 2877).

	* src/frontends/Toolbars.C (layoutSelected):
	* src/MenuBackend.C (MenuItem):
	* src/ToolbarBackend.C (add): adapt to FuncRequest change.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@15825 a592a061-630c-0410-9148-cb99ea01b6c8