Fixing 32550, renaming Ok to Save in the sidebar

xpfe/components/sidebar/resources/customize.css

@@ -85,3 +85,7 @@ box#header > toolbar > .circle {
 box#reorder {
   text-align: center;
 }
+box#saveCancelButtons {
+  margin-bottom: 0.5em;
+  text-align: center;
+}

xpfe/components/sidebar/resources/customize.xul

@@ -124,7 +124,12 @@
 
   </box>
 
-  <box id="okCancelButtons"/>
+  <box id="saveCancelButtons">
+  	<spring flex="1"/>
+	<button oncommand="Save();" id="save_button" value="&sidebar.customize.save.label;" />
+	<button oncommand="window.close();" value="&sidebar.customize.cancel.label;" />
+	<spring flex="1"/>
+  </box>
 
 </window>