Parse limitation warnings as 'text' and in user language

Parse limitation warnings as 'text' and in user language

The default limitation warning messages contains wiki markup to get bold
text, which does not get parsed with 'escaped'

Before using the message class the call was:
wfMsgExt( "$limitationType-warning", array( 'parsemag', 'escape' ),
$current, $max );
This piece of message does not go into the parser cache.

Change-Id: Ibccfacc9a6b9c43491e3b4ca8f5e8f6a6b1efae9