Decoration: add a SetTheme message and releaseResources
Decoration: add a SetTheme message and releaseResources

...which should make it harder to forget to release the font structure.

darcs-hash:20080207184048-32816-9eb5e6f572ed83affeb1f1c726bc0f59e3d90a91

jthornber/XMonadContrib,jthornber/XMonadContrib