Rewrite videojs-chromecast in CoffeeScript

As a first step, i will rewrite the wohle videojs-chromecast plugin with coffeescript.
The code is very unreadable currently. I will leave the JS files until the new code has been tested with a Chromecast.

Update:
There are currently a lot of variables that are not used. I have to refactor it with a lot of testing, before i can rewrite it in CoffeeScript.

Tasks for this Pull request:
* [x] Rewrite all files in src/ in CoffeeScript
* [x] Rewrite Gruntfile to work with CoffeeScript
* [x] Test the re-written code
* [x] Delete all JS Files
* [x] Rewrite the Gruntfile in CoffeeScript