Contents API

Hat tip to @acollign for the work that he did on this to start. I took what he did and essentially added the ability to mutate content using the content API. This still needs some tests added, I think, but I had issues getting them to run? (I think something was screwy with my network connection?)

Anyway, I'm more than happy to add the tests, but I wanted to go ahead and start getting feedback on how this looks. :-)

This would resolve #46