Merge pull request #252 from bmjames/scalaz-seven

Upgrade IO#catchLeft and IO#catchSomeLeft to GlorifiedTuple
Specialize foldLeft for NonEmptyList; foldLeft/foldLeft1 for Tree.
Merge pull request #253 from S11001001/topic/nel-fold-left

Specialize foldLeft for NonEmptyList; foldLeft/foldLeft1 for Tree.