[Xcb] using enums as type in sync.xml

[Thomas Hunger]

Sorry, I missed this comment:

>  (We can't give the enum a size because it may  
> be reused in different requests for fields with differing sizes.)

That would bring back another old thread:

http://lists.freedesktop.org/archives/xcb/2007-June/002908.html

Maybe we should keep the type="CARD32" but introduce an extra tag to 
<field/> and <valueparam/> which describes the possible values. E.g. 
in sync.xml:

  <field type="CARD32" values="ALARMSTATE" name="wait_type" />

This would capture the meaning for higher-level bindings and keep the 
binary level easily checkable against the specs.

Tom