create a small UI that allows a developer to run the test suite when the...

... app is in test mode

This CL surfaces a small UI to allow a developer to run tests locally. It's essentially a small button in the bottom left corner that floats on top of the rest of the UI.

![screen shot 2013-09-26 at 3 16 13 pm](https://f.cloud.github.com/assets/1269969/1222096/7cd8be46-26f9-11e3-9c87-65094bf2d4c8.png)

When clicked, any test output gets logged to the developer console, and the UI's updated w/ the test results:

![screen shot 2013-09-26 at 3 16 20 pm](https://f.cloud.github.com/assets/1269969/1222106/a1512e02-26f9-11e3-9f9f-d3446f2a472d.png)

There's also plumbing in here for automatically trying to connect to a test listener service on startup (this only happens when running in test mode). If one is found, the tests are run automatically and test results are piped over the socket connection.

My next CL will hopefully have a working test listener service. That tool would listen on a certain port, start a Chrome instance running the app, listen for test results, and then either wait for the process to exit or terminate it itself. This service would then be runs on our bots ==> should give us test coverage for each commit and branch for spark.

@keertip @dinhviethoa