example of inter-api compat for new api changes

[Dave Airlie]

Hi,

I've put a branch up that has a header file that covers the new APIs
with compat wrapping as well as I could.

http://cgit.freedesktop.org/xorg/driver/xf86-video-modesetting/log/?h=compat

It covers the 3 api changes currently proposing, the glyph picture
one, the scrn->screen and vice-versa,
and the removal of inidices from the block handler, and scrninfo APIs.

There might be ways to do this less ugly and driver writers can really
do whatever they are happy with,

suggestions for improvements also welcome.

Dave.