Update SemanticWatchlist.hooks.php

* Moved wfMsg depeciated in MW 1.21 to wfMessage
Update SpecialWatchlistConditions.php

* Moved wfMsg depeciated in MW 1.21 to wfMessage
Update SpecialSemanticWatchlist.php

* Moved wfMsg depeciated in MW 1.21 to wfMessage
Update SWL_Emailer.php

* Moved wfMsg depeciated in MW 1.21 to wfMessage
Update GetPreferences.php

* Moved wfMsg depeciated in MW 1.21 to wfMessage
Update ApiQuerySemanticWatchlist.php

* Moved wfMsg depeciated in MW 1.21 to wfMessage
Merge pull request #25 from SemanticMediaWiki/wfm

Update SemanticWatchlist.hooks.php