Converted mathmo to LiveScript, improved unit tests, minor tweaks

1. Converted mathmo to LiveScript.

All the files in `src/scripts/libs/qa` are now LiveScript. There were several sessions of long debugging, but I think all of the questions now have parity with their JS counterparts. They also pass our unit tests, and work without problem in the browser.

2. Improved unit tests

The questions that are tested in the unit tests now start at 1000, rather than 1, so we can compare the questions we’re testing against a working version more easily.

3. Minor tweaks

I started doing this because I needed to debug some of the JS, and in many areas it was easier just to rewrite in LS and start over. There are lots of little tweaks (more than can be comfortably listed) to the questions, but nothing substantial.

I’m working on Vicky’s new questions, but they’re in a separate branch and not quite done yet. I wanted to commit this and just be done with this conversion.