mesa: upgrade to glext.h version 66

The type of the num/count parameter to glProgramParameters4[df]vNV()
changed so some API dispatch code needed updates too.
diff --git a/docs/relnotes-7.10.html b/docs/relnotes-7.10.html
index 6706caf..1f5570d 100644
--- a/docs/relnotes-7.10.html
+++ b/docs/relnotes-7.10.html
@@ -49,7 +49,7 @@
 
 <h2>Changes</h2>
 <ul>
-<li>tbd</li>
+<li>Upgraded glext.h to version 66</li>
 </ul>
 
 </body>