Improve README.

Add a summary section to the README, as well as dependency-checker links
and a license.

Change-Id: I0f1653d52cce6d79347cbe043874069b2f4c6bd4
Add `npm test` target, improve `.jshintrc`, "use strict".

The `npm test` target only runs `jshint` so far -- but baby
steps!  Improve the `.jshintrc` to match that used for Parsoid
and the other `mw-ocg-*` packages.

Change-Id: Ida9b0ddf6761b77edb58b61d9306ee173ed7cbf4