Drawable surface now working in X11 currently the window class keeps only one instance
of a display around. If the display count ever goes to 0 then the display is destroyed
for all windows. The first and the last call are in the constructor of the window
object and in the destructor of that given object. Any other operation in between
will just atomically increment the counter.

Change-Id: I96d77b186b38069c88f9fb1636b20ba9f8a611c6
Reviewed-on: http://www.matthewh.me/gerrit/36
Reviewed-by: Matthew Hoggan <mehoggan@gmail.com>
Tested-by: Matthew Hoggan <mehoggan@gmail.com>