conver the address book directory column header to a sidebar header like firebird

mail/components/addrbook/content/addressbook.xul

@@ -350,6 +350,9 @@ Contributor(s):
   <!-- The main address book three pane -->
   <hbox flex="1">
     <vbox id="dirTreeBox" persist="width collapsed">
+      <sidebarheader id="abDirTreeHeader" align="center">
+        <label id="abDirTreeHeader-title" value="&dirTreeHeader.label;"/>
+      </sidebarheader>
       <tree id="dirTree" style="min-width:150px" flex="1" persist="width"/>
     </vbox>
 

mail/components/addrbook/jar.mn

@@ -5,6 +5,7 @@ messenger.jar:
 +   content/messenger/addressbook/abCardViewOverlay.js          (content/abCardViewOverlay.js)
 +   content/messenger/addressbook/addressbook.js                (content/addressbook.js)
 +   content/messenger/addressbook/addressbook.xul               (content/addressbook.xul)
++   content/messenger/addressbook/abDirTreeOverlay.xul          (content/abDirTreeOverlay.xul)
 
 en-US.jar:
 +   locale/en-US/messenger/addressbook/abMainWindow.dtd         (locale/abMainWindow.dtd)

mail/components/addrbook/locale/abMainWindow.dtd

@@ -114,3 +114,5 @@ Rights Reserved.
 <!-- LOCALIZATION NOTE (hideSwapFnLnUI) : DONT_TRANSLATE -->
 <!-- Swap FN/LN UI  Set to "false" to show swap fn/ln UI -->
 <!ENTITY  hideSwapFnLnUI "true">
+
+<!ENTITY dirTreeHeader.label               "Address Books"> 

mail/components/addrbook/skin/addressbook.css

@@ -232,4 +232,6 @@ html|p {
 #searchBox {
   border-top: 1px solid ThreeDHighlight;
   border-bottom: 1px solid ThreeDShadow;
+  border-left: 2px solid;
+  -moz-border-left-colors: ThreeDShadow ThreeDDarkShadow;
 }