Fix logistration Jasmine tests

Includes several bug fixes caught during test writing, general clean-up, and adds js-url, a lightweight URL parser
Moved to setting ajaxType with passed in method for models and now handling form load fail errors
Added tests.
Merge pull request #5872 from edx/alasdair/logistration-form-errors-and-submit-methods

Moved to setting ajaxType with passed in method for models and now handl...