Remove TODO.md

I've consolidated all our stb-tester ONE todo lists elsewhere.
.gitignore: Remove unnecessary entries

These came from angular-seed, but I don't know what they are, or what
"!.gitkeep" means. I don't have any of these files lying around. I'll
leave ".DS_Store" there in case we ever have contributions from Mac
users.
Move jshint config from package.json to .jshintrc

...overwriting the `.jshintrc` we inherited from angular-seed.
(I didn't realise that `.jshintrc` already existed when I added our own
jshint config to `package.json` in b0ecc1e.)
Correct the license in package.json to match README (license = undecided)
README: Cleanup list of dependencies (each one on its own line)

To make future diffs clearer.
e2e-tests: Rewrite tests in python instead of javascript

This will make it easier for me to write integration tests in the
future. For example, a test that does a `git push` to the test-pack git
repo on the backend, and verifies that the list of tests is updated in
the Web UI.

This uses python-selenium[1]. The main functionality we'll miss from
protractor are Angular-specific locators, like `by.binding`; we'll have
to make do with CSS selectors instead.

[1] http://selenium-python.readthedocs.org/en/latest/index.html