Force root of bookmarks tree to be open (apparently required, at least for the moment, due to ongoing XUL tree changes).

xpfe/components/bookmarks/resources/bookmarks.xul

@@ -137,7 +137,7 @@
     </treerow>
   </treehead>
 
-  <treechildren id="NC:BookmarksRoot" />
+  <treechildren id="NC:BookmarksRoot" open="true" />
 </tree>
 
 </xul:window>