WINTERMUTE: Remove _tempDisableDirtyRects
WINTERMUTE: Add a DirtyRectContainer to generate multiple dirty rects
Merge branch 'wme_multirect' into wme_rendering

Conflicts:
	engines/wintermute/base/gfx/osystem/base_render_osystem.cpp
	engines/wintermute/base/gfx/osystem/base_render_osystem.h
WINTERMUTE: Properly clear wantsDraw if optimized is empty
WINTERMUTE: Fix one multi-rect intersection case
WINTERMUTE: Avoid painting empty parts of UITiledImage

This fixes a crash in the Chivalry options menu.
WINTERMUTE: Clean up DirtyRectContainer a bit
Merge branch 'master' into wme_rendering

Conflicts:
	engines/wintermute/base/gfx/osystem/base_render_osystem.cpp