In which we finally begin front-end development against the back-end

The front-end can finally show, edit and create two fields on a quest using the back-end:
- added getters & setters for simple resources
- added a view for quests to view/edit/create basic quest fields
- pulled in a package named angular-xeditable for easy in-line editing

Two updates to the backend to make it easier to work with:
- null values are treated equivalently to values absent from the payload
- the full resource representation is returned on a PUT

@maiamcguinness -- feel free to ignore the Python, but do please look at my first Angular doodles.  We really need to get testing sorted.