Add a catch-all constructor to the set of mouse buttons.
Add a catch-all constructor to the set of mouse buttons.

darcs-hash:20071004144115-e1dd6-c6f5db3420beb7e714b3b8b96b280739b672fa68.gz

thiagoarrais/gtk2hs,thiagoarrais/gtk2hs,thiagoarrais/gtk2hs