move import out of auto-generated area
`Ops` traits are now sealed abstract classes

This communicates that users should not extend these classes directly
and should also allow for adding methods without breaking binary
compatibility.
add toRight and toLeft to OptionT which return an EitherT
Move liftSemigroup to Semigroup; privatize implementing traits.
Follow liftSemigroup rename.
Merge pull request #432 from S11001001/topic/move-lift-semigroup

Move liftSemigroup to Semigroup; privatize implementing traits.
Merge pull request #430 from stew/scalaz-seven

add toRight and toLeft to OptionT which return an EitherT
Merge pull request #429 from larsrh/topic/sealed-ops

Change `Ops` traits to be sealed abstract classes