[Xcb] GLX progress

[Jeremy Kolb]

It's almost done, I just can't figure out how to express the strings in 
the VendorRequest and VendorRequestWithReply requests.  The length of 
the strings is not specified so I'm unsure, can I just do field with 
type="char *"?  Can someone double check?

Once I figure that out and the bug in the xslt thing's fixed (how 
value-mask in a reply is ignored [I looked at it but couldn't figure out 
what's going on]) then this should be in a somewhat useable state.

Here are the vendor requests:

	<request name="VendorPrivate" opcode="16">
		<field type="CARD32" name="vendor_code" />
		<list type="BYTE" name="data"></list>
		<!-- FIX: Not sure what the length is on this list -->
	</request>

	<request name="VendorPrivateWithReply" opcode="17">
		<field type="CARD32" name="vendor_code" />
		<list type="BYTE" name="data"></list>
		<!-- FIX: Not sure what the length is on this list -->
		<reply>
			<pad bytes="1" />
			<field type="CARD32" name="retval" />
			<list type="BYTE" name="data1">
			    <value>24</value>
			</list>
			<list type="BYTE" name="data2">
			    <fieldref>length</fieldref>
			</list>
		</reply>
	</request>

I'm using the spec from opengl.org: encode1.3.ps if someone wants to 
take a look.

Jeremy