documentation patch: mention PostfixOperators
documentation patch: mention PostfixOperators

Ignore-this: 20a05b1f396f18a742346d6e3daea9a8

darcs-hash:20111210234820-76d51-9e61d010d8e3f8cc477e4db4ec41f0985c588233

jthornber/XMonadContrib,jthornber/XMonadContrib