Fixes to integrate with newest version of khan-exercises.
Hide related videos on exercises when video isn't available.
Added version 1.9.1 of jQuery to support new khan-exercises.
Updated khan-exercises to newest version.
Correct path to raphael.js on knowledge map.
Updated Khan API data via khanload, after removing exercise blacklist.
When normalizing the knowledge map layout, avoid flipping coords twice.
Updated topic data with double-dimension-flipping removed.
Merge branch 'develop' of github.com:learningequality/ka-lite into new_khan_exercises

Conflicts:
	kalite/main/views.py
Removed all old versions of jQuery, and standardized references to 1.9.1
Fix to loadtesting view to match new get_or_initialize return signature
Merge pull request #837 from jamalex/new_khan_exercises

Integration of up-to-date khan-exercises codebase, plus some related fixes