fixed double clicking ajax request error for sections and people

added an alreadyClicked parameter to the ajax methods for deleting sections and people. The parameter will be set to true on first click and stored in the nodes data attribute. The value will be set to false upon ajax success or error. If the node is click repeatedly it will only process the ajax request for the first click. This pull request also include local.txt with the django-auth-lti setup pointing to the master branch.
We probably want to put some kind of fade out on the messages div