type class Optional[F[_]]

- abstracts over containers/contexts which may provide a value or not

- instances:
  - scala.Option
  - scalaz.LazyOption

- provides syntax.OptionalOps

- tests for all the functionality
merge branch scalaz-seven
integrate Optional into GenTypeClass
provide concrete orElse in Optional
provides nonEmpty as an alias for isDefined for Optional
provides Optional instance for scalaz.\/
provides Optional instance for LazyEither
provides Optional instance for Validation
Port of Data.Map to scalaz

This is a port of Haskell's Data.Map into scalaz. There are a few things
that need to be considered regarding the usage of sys.error (as per the
implementation in Haskell. It would be advantageous to have all functions
total.

Additionally there are some functions that might still be required, but
the majority of the useful functions have been provided. Feedback is
greatly appreciated.

Signed-off-by: Gary Pamparà <gpampara@gmail.com>
Don't mix context bounds and implicit params for 2.9.x

Signed-off-by: Gary Pamparà <gpampara@gmail.com>
Correct a typo resulting in switched partitioning.

Thanks to @xuwei-k for pointing this out. Added additional tests to check this
more thoroughly.

Signed-off-by: Gary Pamparà <gpampara@gmail.com>
Added mapOption and mapEither functions.

Signed-off-by: Gary Pamparà <gpampara@gmail.com>
cleanup These
These Arbitrary
TheseTest
fix typo
update SBT and plugins
use sbt-unidoc plugin
update to Scala 2.10.2
Merge pull request #451 from larsrh/topic/update-sbt

update SBT & Scala versions