Initial specs (Wincent Strings Utility, 46693cf)

This is an initial batch of specs written using RSpec. Seeing as this is such a simple tool there doesn't seem to be much sense in doing internal testing at the Objective-C level; instead just run the tool itself and make sure it does what it's supposed to do. RSpec is used despite the fact that wincent-strings-util has absolutely no Ruby in it, simply because it's a nice framework for doing this kind of thing.

Signed-off-by: Greg Hurrell <greg@hurrell.net>