(bug 42941) Add $CHANGEDORCREATED back for custom template

1. Add $CHANGEDORCREATED back so custom template with this variable won't break.
   Scheduled for removal in MediaWiki 1.23.
2. change escaped() to text() since this is just plain text email and client
   will interpret it as plain text

Change-Id: I7d9fd90519a68dd66f99479a7c92f6c664485a9c