added a Task.start method to start the future right away
More in-depth ScalaDoc for `\/`
Add documentation to ==>>

I had never used `==>>`, so I thought it would be nice to start looking
through its source, adding ScalaDoc comments as I went along.

This is  how far I got before I thought to check how many lines
were in the file. Adding documentation for the rest is a bit of a
daunting task, but I figured I might as well contribute what I had
already done.

:-\
add a MaybeT, this is basically just a direct translation of OptionT
changes suggested by @ceedubs :wq
rename `start` to `unsafeStart`
Merge pull request #684: Task.start
Merge pull request #733 from stew/call-me-maybet

Call me maybet
Merge pull request #710 from ceedubs/docs-disjunction

More in-depth ScalaDoc for `\/`
Merge pull request #711 from ceedubs/docs-map

Add documentation to ==>>
Add an ensure method to Task similar to \/ or EitherT
Merge pull request #738 from stew/task-ensure

Add an ensure method to Task similar to \/ or EitherT
MonadError type class, \/ implementation, tests.
EitherT implementation.
LazyEither implementation.
LazyEitherT implementation.
Task implementation.
Remove redundant test.