WIP: Adding grabber

This patch series intend to improve !7 implementation by utilizing libxcb instead of xlib and by trying to make it a bit more generic. Using XCB allows x capturing with better errors handling (playing with x errors handler is not needed) and safer x protocol calls.

To test this i mostly used something like:

for i in $( xrandr | grep "\." | awk '{print $1}' | sort -R) ; do (xrandr -s $i ; sleep 1) ; done