Update to StudyPlannr

I’ve just updated StudyPlannr with some new AJAX-y operations. You can now change timing and remove schedule items without waiting for the entire page to reload. As part of this, I’ve also added methods to fetch the entire list of items as JSON. This should make future apps that use the same data much easier.

Next, I’ll probably move more of the operations to work without page refreshes. I’d also like to do some refactoring to try to break down the main python file and the increasingly large chunk of JS embedded in the HTML.