Directfb Backend

["Mike Emmel" <mike emmel gmail com>]

I just checked in a redo of the directfb cairo backend to remove
secondary buffers.
This is in Cairo git  it also fixed subsurface issues.

Next the gdk directfb backend now implements paintable so the
additional pixma buffering is removed.

There are a lot of basic changes in this checkin and a good chance
that some things are broken. But its the last major work I plan to do
on the core drawing since now its basically correct and we can focus
on remaining bugs.

Sorry it took so long to get out.
Please test esp with the debian installer.

Now I can look at debian installer bugs agian !


Mike