Use strict parameter on in_array() checks in wfMsgExt(). In PHP 5.1.6 this was whingi...

Use strict parameter on in_array() checks in wfMsgExt(). In PHP 5.1.6 this was whinging when a Language object was passed as 'language' parameter, trying to convert it to an int (!?).
Since we're only checking for exact strings, an exact match is just fine and it stops the whinging. (Saw no such problem on 5.2.6.)

Example whinge:
Notice: Object of class Language could not be converted to int in /Library/WebServer/Documents/trunk/includes/GlobalFunctions.php on line 742