Create Angular boilerplate

Angular boilerplate generated using Yeoman. We haven't talked about
nginx setup yet, so for now, the results can be viewed by running
python -m SimpleHTTPServer 8000 from inside js/angular/app.

We are not planning to generate controllers, etc. using yeoman (e.g. `yo
angular:controller`) because this won't let us separate angular into modules by function.

This is almost pure boilerplate, but flag anything that looks totally crazy; I already had to remove a .htaccess file that it made.