Update SBT version

Also update the `sbt` script.
Add leftMap method to data types that have Bifunctor instances
Set is not a Functor
IRWST, zooms, `ListenableMonadWriter`
Rerouted standalone `Kleisli` `local`

See pull request discussion.
Merge pull request #281

This pull request adds `colocal` to `WriterT` and `UnwriterT`, `local` to
`ReaderT` (a.k.a. `Kleisli`), and `zoom` to `IndexedStateT`. These methods
allow a transformer of one index type to be morphed into a transformer of a
different index type.  More specifically:

* `colocal` transforms a `WriterT[F, W, A]` (resp. `UnwriterT[F, U, A]`) into a
  `WriterT[F, X, A]` (resp. `UnwriterT[F, X, A]`) using a function of type
  `W => X` (resp. `U => X`).
* `local` transforms a `ReaderT[F, R, A]` into a `ReaderT[F, X, A]` using a
  function of type `X => R`.
* `zoom` transforms an `IndexedStateT[F, S1, S2, A]` into an
  `IndexedStateT[F, X1, X2, A]` using a `LensFamily[X1, X2, S1, S2]`.

In addition, this pull request generalizes `ReaderWriterStateT` to
`IndexedReaderWriterStateT`, although the entire RWST segment of Scalaz 7 could
use some more love.
Use getOrElseUpdate to simplify implementation for mutable maps
Merge pull request #283
Merge pull request #276 from larsrh/topic/set-functor

Set is not a Functor
Merge pull request #285 from mpilquist/leftMap

Add leftMap method to data types that have Bifunctor instances