Fixes exercises.json to include basepoints
Updates topics.json to include 'title' in denormed exercise data.
Implements first pass of playlist view for leaf nodes of topic tree.
Merge branch 'hackathon' of github.com:learningequality/ka-lite into hackathon

Conflicts:
	kalite/distributed/hbtemplates/distributed/sidebar.handlebars
	kalite/distributed/static/js/distributed/topics.js