Change the unit tests to bypass issues caused by touchevents.
* Prefix the generic class names for the themes with `.switch-` to avoid conflicts. So now we have `.switch-android`, `.switch-candy` and `.switch-ios`. Fixes #18
* Changes to the old-Webkit bug-fix, to try and resolve issues with old Android on new devices (with high density screens). Fixes #17
* Improve the Qunit tests, to bypass issues caused by touch events on some mobile platforms.