Use XCB abstraction to Xlib for communication to X11 server. The following
additional changes were needed:

- Split modules/video_output/xcb/xcb_vlc.c in 2
	xcb_vlc.h	 - SHM and PictureResourceAlloc/PictureResourceFree
	xcb_events_vlc.h - matches implementation of modules/video_output/xcb/events.c