fix for 80281 - no sidebar panels in sidebar customize dialog.

convert a treecol->treecolgroup. Seems to fix the visual errors.
adjust window creation flags.
r=matt, sr=blake

xpfe/components/sidebar/resources/customize.xul

@@ -143,9 +143,9 @@
             </action>
           </rule>
         </template>
-        <treecols>
+        <treecolgroup>
           <treecol flex="1"/>
-        </treecols>
+        </treecolgroup>
          <!-- We explicitly create a 'treechildren' so we can refer
               to it from the script -->
         <treechildren id="current-panels-root"/> 

xpfe/components/sidebar/resources/sidebarOverlay.js

@@ -779,7 +779,7 @@ function SidebarCustomize() {
 
       customizeWindow = window.openDialog(
                          'chrome://communicator/content/sidebar/customize.xul',
-                         '_blank','centerscreen,chrome,resizable',
+                         '_blank','centerscreen,chrome,resizable,dialog=no,dependent',
                          sidebarObj.master_datasources,
                          sidebarObj.master_resource,
                          sidebarObj.datasource_uri,