rewrite to CoffeeScript

Hello there,

First, thanks for a nice plugin.

I needed to add the possibility to specify row & cell selectors for your plugin, and on that occasion rewrote it to CoffeeScript, which in my opinion results in a bit cleaner code.

I also made a slight changes to the generated markup and added few more options.

If you'd want to merge this into your branch please feel free to go ahead.

Best wishes,
Tomas