Merge commit '381d5e209815235911c4aab516037c868c8f695f'

This merges the patches from the series "[PATCH 00/14] More
client-side GLX house cleaning" that were posted to the mesa3d-dev
mailing list.  See
http://marc.info/?l=mesa3d-dev&m=126582985214612&w=2

Patches 01 through 04 eliminate a bunch of annoying warnings that I
get when building Mesa.

Patch 05 fixes an inconsistency between the implementation of
glXSwapIntervalMESA and the spec.  I chose to favor the code over the
spec in this case.  This also eliminated a warning.

Patches 06 through 12 clean up the way that context creation is
performed on the client.  When support for GLX_SGIX_fbconfig and the
related GLX 1.3 functions was added, I refactored a bunch
nuts-and-bolts of context creation to CreateContext.  The refactor was
a good idea, I just didn't do it right.

Patches 13 and 14 update glxgears_fbconfig to use GLX 1.3 interfaces.

docs/MESA_swap_control.spec

@@ -43,7 +43,7 @@ Issues
 
 New Procedures and Functions
 
-    int glXSwapIntervalMESA(int interval)
+    int glXSwapIntervalMESA(unsigned int interval)
     int glXGetSwapIntervalMESA(void)
 
 New Tokens
@@ -103,11 +103,8 @@ Additions to the GLX 1.3 Specification
 
 Errors
 
-    glXSwapIntervalMESA returns GLX_BAD_VALUE if parameter <interval> is
-    less than zero.
-
     glXSwapIntervalMESA returns GLX_BAD_CONTEXT if there is no current
-    GLXContext.
+    GLXContext or if the current context is not a direct rendering context.
 
 GLX Protocol