Keyboard api2

So, here we are again, with a completely re-written keyboard API. This one now supports RESTFUL HTTP access with GET/POST/PUT/DELETE, and has a clean URL structure. It also moves counter.js into the cc_kapi subdirectory for ease of maintenance. 

Counter.js has had a bit of a re-write to access the JSON dictionary which contains the mapping, as it now also contains keyboard-related meta-data for the purposes of saving and retrieving multiple keyboards for a given user. There is a complete test suite, though it doesn't check the validation of every field, as it uses the default validators from django-rest-framework, which are tested there.