Bug fixes

Hey Joe.
While working through the homeworks (I am taking Lance's CS522 class) found couple of bugs.
Interpolation wasn't working for non square images, so I fixed that and changed implementation on outline. In detail:
getOutlineArray is not concerned with actual values of the pixels since it only works only on binary images, so I converted it to work on Vectors of Bools instead, biggest reason was it was impossible (although you had an example in the doc) to construct a ColorImage with outline' (by the way I would rename it to outlineColor, since outline is just for binary) due to the type constrain, implementation itself was correct. Anyways I'll keep em coming as class progresses. I have an idea of trying to use Accelerated package to use GPU for computations, I expect it would become blazing fast then, but I am still getting used to unm-hip, so don't know if it's possible. Great job by the way on the library.
Also please check the functionality of my changes if you can, they work for me, but who knows.
Alexey.