Remove duplicated files. (It's part of ticket #1178).
Pullup additional patches requested by mrg in ticket #308:

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.