84344 - defer skin switch to restart.

r=danm, sr=hyatt, a=chofmann.
navigator.properties - add notifcation string ('changes will take effect on restart')

xpfe/browser/resources/locale/en-US/navigator.properties

@@ -45,4 +45,6 @@ nothingAvailable=(Nothing Available)
 oldthemetitle=Warning: incompatible theme
 oldTheme=You have selected a theme which was designed for an earlier version of %brand% and is incompatible with your current %brand% version. Please check the %brand% Theme Park for an updated version of the theme. You can uninstall this theme by clicking \"OK\" button.
 
-
+# XXX - this sucks and should only be temporary.
+switchskins=Theme changes will take effect when you restart %S.
+switchskinstitle=Apply Theme