Make tp:value-ref's type attribute optional
Make tp:value-ref's type attribute optional

* Also: don't ever rewrite the node's text. This means:
 * If you want the long-form, use:
   <tp:value-ref>Type_Name_Value</tp:value-ref>
 * If you want the short form, use:
   <tp:value-ref type="Type_Name">Value</tp:value-ref>

This changes the html output of all current value-refs to use the
short form.

TelepathyIM/telepathy-spec,freedesktop-unofficial-mirror/telepathy__telepathy-spec