Removed jquery dependecy from keyboard plugin and corrected tests

Hi Dan,
sory for obtrusiveness, I just want to speed up jemul8, if remove jquery dependency or move out it to google cdn if would work a little bit faster. Any way you use it in a couple places and wanted to remove it, as you write in todo of [util.js](https://github.com/asmblah/jemul8/blob/master/js/core/util.js#L29)

Corrected tests for pull request https://github.com/asmblah/jemul8/pull/8.
Tests works fine in Chrome and FF.