Add addon config

[zpao]

Thoughts @JakubMal? We talked about this briefly with #13 and wanted to hear your opinion before I pushed it out.

(ignore the coffeescript commit, that'll be pushed to master on its own, didn't mean for it to end up here)

[zpao]

PS this works, but don't know a good way to actually test the combos outside of making an app and requesting assets/application.js (would be 4 different apps here? or maybe we can set config in each test run and restart the app?)

[jtmalinowski]

A lot of catching up to do on my side... can't tell you right now from the top of my head, but there surely is a nice way! If you're fine with that, I would add tests for this in #12 Yeah I know I'm kinda late - but I'm very positive I'll have time to finish it this weekend! Btw, I would love to start using coffee in jsx so much, that it makes me want to finish #12 today :)

[zpao]

Well, I messed up the github flow, but landed the change here in f299db0

[zpao]

@JakubMal if you think of a better way to expose addons, let me know. I haven't released this yet (almost did) but it seemed like the best thing short term.

[jtmalinowski]

That looks fine, I would go for unit tests here, what do you think?

[zpao]

Would love unit test. I'm not sure what the best way to do it is though so I'm open to ideas.