* Removing all the messages about stewards from all the langauge files:

* Removing all the messages about stewards from all the langauge files:
** The steward group messages ("group-steward" and "group-steward-member") should be defined in Makesysop (where the group is defined), therefore they are being moved to there.
** The messages about stewards in Makesysop ("setstewardflag" and "already_steward") are unused and were removed from Makesysop messages, therefore they are now removed from here.
* A little improvement for checkLangauge.php: you can now skip all the checks, and check only the syntax - useful if you change a lot of language files and want to know if you didn't break the syntax.