514 clickable tabs 2

Rebased the tagging branch to current develop.

While working on the previous branch, I believe I have resolved all of @tilgovi's concerns, except one suggestion to change the directive from an element to an attribute (on the input element), which I don't think is feasible in this case. (Because of the structure of the DOM elements the tag-it widget uses.)

Please review if you must, and then merge :)