kwin4 renamed to KFourInLine

[Albert Astals Cid]

Ok, so i renamed from kwin4 to KFourInLine given the kdegames IRC meeting 
consensus and Martin that is the maintainer agreeing.

I'm almost sure i've done everything needed so that it works, i could start a 
game and play, but obviously double checking everything works as expected is 
welcome.

Non user visible strings like classes names and stuff have not been changed 
(i'm not THAT crazy)

Albert