* gdk/gdktypes.h:
	Add new type GdkSpan

	* docs/reference/gdk/gdk-sections.txt,
	docs/reference/gdk/tmpl/regions.sgml, gdk/gdkregion-generic.c,
	gdk/gdkregion.h:
	Implement and document gdk_region_spans_intersect_foreach.

	* gdk/linux-fb/Makefile.am, gdk/linux-fb/gdkrender-fb.c:
	Add new file gdkrender-fb.c which contains all core
	rendering code.
	Add gdk_fb_fill_rectangle_generic (old rectangle code) and
	gdk_fb_fill_rectangle_simple_16, gdk_fb_fill_rectangle_simple_32
	(optimized rectangle fillers).

	* gdk/linux-fb/gdkdrawable-fb2.c:
	Move all rendering code to gdkrender-fb.c.
	Change from using GdkRectangles and GdkSegments for spans to GdkSpan.
	Use the new span intersection functions in gdk_fb_fill_spans.
	gdk_fb_draw_rectangle() clips filled rectangles and calls
	gc->fill_rectangle with the result.
	gdk_fb_fill_spans() gets extra argument "sorted".

	* gdk/linux-fb/gdkevents-fb.c:
	Remove unused includes and defines.
	New function gdk_fb...