* Switched qunit dependency to npm
* Fixed testem not working
* Switched test.js build to use node-qunit.
As stated in the QUnit docs: The qunit package prior to 2.4.1 is an alternative CLI that is now published as node-qunit.
* Introduced qunit 2.4.1, with an npm script for running node tests
* Switched testem page fixture to use qunit package instead of qunitjs
* Configured testem to run in headless mode, and use new npm node test script for "Node" launcher configuration.
This means that individual tests will show up in testem output via the the `tap` test protocol.
* Made canvas_static 'toDataURL cropping' test asynchronous.
* Configured QUnit testTimeout and enabled 'noglobals' config
* Updated .travis.yml config to do cross-browser/env testing via Testem
* Specify qunit binary directly to fix confict with binary from node-qunit
* Avoid test hanging by aborting the animated cursor
* Firefox test fix, and enabled in Testem config
