kpreid | Cubes update

Some new features in Cubes:

An automated test suite. It’s hardly complete coverage, but at least it exists and so can grow. (I ended up going with Jasmine for in-browser testing. I’m not a big fan of the Englishy syntax, but it does the job reasonably well and has niceties like rerunning individual tests and adequate support for asynchronous tests.)
Precise collision against rotated blocks: you can now walk up the slope of those funky pyramid blocks, and so on. Stairs, anyone?
Performance monitoring widget with fancy graphs. (If you click the “[-]” to hide it, then it won’t waste CPU time updating itself, either.)