Ver0.3

Pinging @gregwebs. I applied a transformation to the SafeSequence and OrdNonNull typeclasses: by placing partial versions of the functions in IsSequence and OrdSequence, we can generalized the members of this typeclass to any instance of NonNull. This avoids the need to define extra typeclass instances, which actually prevented me from writing some code in [a new project of mine](https://github.com/fpco/conduit-combinators/).

I've applied a similar transformation to MonoFoldable1 in https://github.com/snoyberg/mono-traversable/commit/60c17e4e23d9f81aeb272d9e7d775add045c0018.

I don't see any downside to this changes: we keep the efficient underlying implementations if they're available, and otherwise get all the same type safety we have with the current approach. Any objection to merging this to master?