Add more matchers for FJ data types

[GoogleCodeExporter]

To continue the Revolution, instinct needs a few more matchers of data
types from functional java:
eg.
expect.that(Option.<Integer>some(5).isSomeWith(5); //horrible name, I think

A list of potential matchers:
* Option
** isNone
** isSome
** isSomeWith(value)

* Either
** isLeft
** isRight
** isXxxProjectedWith(value)

Feedback on the names we should adopt here, and more matchers, would be good.

Original issue reported on code.google.com by nkp...@gmail.com on 28 Jul 2008 at 7:03