Merge branch 'backbone' of https://github.com/jamalex/ka-lite into backbone
Fix student_testing.
Implement start and stop screens for tests.
Merge branch 'backbone' of https://github.com/jamalex/ka-lite into backbone

Conflicts:
	kalite/student_testing/models.py
Add context_type filtering to AttemptLog Resource.
Filter AttemptLogCollection fetching by context_type.
Moved style block CSS from exercise.html into khan-lite.css
Moved some dummy JS definitions from exercise.html into exercises.js
Dynamically add exercise-inline-style <style> block to page.
Moved khan-exercise.js reference down to the other JS file imports.
Removed obsolate TODO block.
Replace urlBaseOverride with direct building of the khan-exercises URL.
Move statusModel load deferral into ExercisePracticeView.
Use a deferred for indicating khan-exercises loading status.
Basic unstyled version of playlist view page with exercises loading.
Fix sequencing of tests.
TODO: Get start of test to work without reload.
Make answer question button identical on incorrect or correct answer in test mode.
Add a (hopefully unique) random ID to the video.js video element.
Avoid initializing video player more than once, but only within instance.
Remove duplicated javascript imports.
Get videos loading on playlist page.
Merge branch 'backbone' of https://github.com/rtibbles/ka-lite into backbone

Conflicts:
	kalite/distributed/static/js/distributed/exercises.js
	kalite/distributed/templates/distributed/exercise.html