Pullup additional patches requested by mrg in ticket #1935:

xsrc/external/mit/xorg-server/dist/exa/exa_render.c  1.2
xsrc/external/mit/xorg-server/dist/render/picture.h  1.2

	fixes for CVE CVE-2013-6424:
	If t->bottom is close to MIN_INT, removing top can wraparound, so do
	the check properly.