Updates and a few bug fixes.

- Replacing JSMin with JShrink\Minifier (https://github.com/tedivm/JShrink)
- Fixing bug that would force assets to be cached and parsed even if "cache" => false
- ScriptAsset output now always puts "\n;" after file contents to help prevent invalid combined output.
- StyleAsset output now always puts "\n" after file contents to help prevent invalid combined output.

Still to do:
- Explore Less implementation
- Update README.MD
- Additional testing.