Refactor the code to emit multiple-inclusion protection to
FilterGLAPISpecBase.  Since the size_h mode of glX_proto_size.py will be
used to generate multiple header files, add an option to specify the define
that is used for multiple-inclusion protection.

The changes to the header files in this commit are just a side-effect of the
changes to the Python scripts.
diff --git a/src/mesa/glapi/gl_table.py b/src/mesa/glapi/gl_table.py
index d59d3de..49a8af7 100644
--- a/src/mesa/glapi/gl_table.py
+++ b/src/mesa/glapi/gl_table.py
@@ -38,6 +38,7 @@
 
 	def __init__(self):
 		gl_XML.FilterGLAPISpecBase.__init__(self)
+		self.header_tag = '_GLAPI_TABLE_H_'
 		self.license = license.bsd_license_template % ( \
 """Copyright (C) 1999-2003  Brian Paul   All Rights Reserved.
 (C) Copyright IBM Corporation 2004""", "BRIAN PAUL, IBM")
@@ -51,9 +52,6 @@
 			(f.fn_return_type, f.name, arg_string, f.fn_offset)
 
 	def printRealHeader(self):
-		print '#ifndef _GLAPI_TABLE_H_'
-		print '#define _GLAPI_TABLE_H_'
-		print ''
 		print '#ifndef GLAPIENTRYP'
 		print '#define GLAPIENTRYP'
 		print '#endif'
@@ -64,8 +62,6 @@
 
 	def printRealFooter(self):
 		print '};'
-		print ''
-		print '#endif'
 		return