added boolean property gtk-touchscreen-mode, which essentially means

added boolean property gtk-touchscreen-mode, which essentially means

2006-02-22  Michael Natterer  <mitch@imendio.com>

	* gtk/gtksettings.c: added boolean property gtk-touchscreen-mode,
	which essentially means "there are no motion notify events", so
	widgets can't use the pointer hovering them for anything.

	* gtk/gtkmenu.c: if gtk-touchscreen-mode is TRUE, scroll menus
	when clicking the scroll arrows, since hovering goes undetected.
	Fixes bug #323028.

	Added boolean style property "double-arrows" which always makes
	both scroll arrows visible when the menu is too long.
	For pushed-in popup menus, both arrows are always shown
	(regardless of double-arrows), in order to fix user confusion
	about the blank area. Fixes bug #129463.