Add a "count" attribute to "enums" elements to set the default count
used for "size" sub-elements.  In the future the "count" attribute may
be removed completely from "size" sub-elements, so gl_API.xml was also
updated.

Support was added for a (currently unused) "mode" attribute for "size"
elements.  Basically, functions are marked as either "get" or "set".  This
will be used in generating size functions for the server-side (where the
"get" functions have to know how much data to return).  It could also be
used to help generate code for src/mesa/main/get.c.
diff --git a/src/mesa/glapi/glX_XML.py b/src/mesa/glapi/glX_XML.py
index 4c9da6e..9d8fe00 100644
--- a/src/mesa/glapi/glX_XML.py
+++ b/src/mesa/glapi/glX_XML.py
@@ -244,7 +244,7 @@
 
 	def startElement(self, name, attrs):
 		if name == "size":
-			[n, c] = self.process_attributes(attrs)
+			[n, c, mode] = self.process_attributes(attrs)
 
 			if not self.context.glx_enum_functions.has_key( n ):
 				f = glXEnumFunction( n )