Add test documentation

[savagejen]

The tests look good, but it's hard to tell exactly what they're doing without diving into their code. It would be nice if there was something like gherkins written that describe the specific application behavior being tested for, included in the comments of the test code. This would make it easier to look for logic flaws. (Yes, I realize there is already documentation for pond. I am merely suggesting that this be integrated into the tests in a standardized format.)

[agl]

Although a perfectly reasonable desiderata, I think the lack of test coverage is the bigger problem at the moment. The CLI, for example, is not tested at all. After fixing the GUI situation on OS X, I think this is priority #2.