rename 'uri' (and parent_uri) to 'mid' (and parent_mid) since these no longer remotely resemble uri's and are actually message_id's. This change is potentially destabilising because it touches a lot of code and structure. But it has to get done and there's no better time than the present.

view/tpl/event_form.tpl

@@ -8,7 +8,7 @@ $desc
 
 <input type="hidden" name="event_id" value="$eid" />
 <input type="hidden" name="cid" value="$cid" />
-<input type="hidden" name="uri" value="$uri" />
+<input type="hidden" name="mid" value="$mid" />
 
 <div id="event-start-text">$s_text</div>
 $s_dsel $s_tsel