xserver: Changes to '1.5'

[Kristian Høgsberg]

New branch '1.5' available with the following commits:
commit 2156bdf3b7b5b7d3ee4d3278eac0f28c7bff830a
Author: Kristian Høgsberg <krh at redhat.com>
Date:   Wed Mar 26 19:28:09 2008 -0400

    Implement DRI2 direct rendering and update AIGLX to DRI interface changes.
    
    Get rid of glcontextmodes.[ch] from build, rename __GlcontextModes to
    __GLXcontext.  Drop all #includes of glcontextmodes.h and glcore.h.
    Drop the DRI context modes extension.
    
    Add protocol code to DRI2 module and load DRI2 extension by default.
    (cherry picked from commit c40e0b51f0d9ef5e1f30f233d7db1e6db9d6681b)