ThreeColumns support middle column, with more backwards compatiblity
ThreeColumns support middle column, with more backwards compatiblity

Ignore-this: 5a8991269904986e0e012e955c6d4712

darcs-hash:20090414061819-1499c-fe2d526b41d0224f363e586c392d93f60584b51c

yzhou61/xmonad-contrib,yzhou61/xmonad-contrib,yzhou61/xmonad-contrib