Optimized omapM_ for Maybe

For an example of why this is important, see:

https://github.com/snoyberg/conduit/commit/11877684b3adb7ca422ae5000fab1ebeb3fbe142
Whitespace fix
Version bump
Documentation fix
document mono-traversable vs. lens Traversal
unsnoc test
Whitespace fix
More efficient unsnoc
another point for lens comparison
Added a bunch of INLINE pragmas
Workaround for #24
Strict osum/oproduct
foldl integration

Pinging @Gabriel439. I went with the `Unwrap` nomenclature, which seems
to work just fine. But if you have a different naming scheme you'd
prefer gets used with foldl, let me know.
Merge branch 'master' into minlen

Conflicts:
	src/Data/MinLen.hs
	src/Data/NonNull.hs