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.
So, the P.O. thinks that we should just keep it as is - it's very unlikely that the end user will see the 'unprocessible' message since that only gets thrown if attempting to delete a primary section and we don't allow that in the UI.  A story was added to the backlog to take another look at error handling in general for sectioning.