TilePrime.hs: Correct behavior when number of windows <= nmaster
TilePrime.hs: Correct behavior when number of windows <= nmaster


Additionally this patch does various clean-ups that should not
affect functionality.

mathstuf/xmonad-contrib,mathstuf/xmonad-contrib,CaptainPatate/xmonad-contrib,f1u77y/xmonad-contrib,0/xmonad-contrib,ohlus/xmonad-contrib,CaptainPatate/xmonad-contrib,mathstuf/xmonad-contrib,ohlus/xmonad-contrib,f1u77y/xmonad-contrib,xmonad/xmonad-contrib,ohlus/xmonad-contrib,pjones/xmonad-test,0/xmonad-contrib,xmonad/xmonad-contrib,CaptainPatate/xmonad-contrib,0/xmonad-contrib