Revamp the Asset Handling

* Remove webassets
* Add an invoke task for building the less files and running wake to build the distribution files
* Add an URL helper to generate the static urls
* Remove the requirement to run less unless you're working on the design
* Add the requirement to run wake if you're not working on the design
* Add ``theme_debug`` which will run less in the browser and enable easy iteration on the theme itself.
* Removes bower and manually bundles our javascript and css dependencies (jquery and bootstrap).