Added bower for package management

This pull request would add bower for all client-side 3rd-party dependencies. This would greatly improve manageability of our dependencies & discourage contributors from directly modifying these files (as happened with the video.js files).

I've moved all video.js theme files to their respective new locations and moved `settings.js` out of the `vendor/`  directory. Furthermore all dependencies are updated to their latest version, something that we can do more easily with Bower in the future as well.