remove infinite loops from management commands. remove cruft from api_views, and tweak video_download to handle the more robust videodownload logic
updating comments, debug-based Exception forcing, to complete.
Merge branch 'release-0.10' of github.com:learningequality/ka-lite into avoid_command_infinite_loops

Conflicts:
	kalite/templates/video_download.html
Merge branch 'avoid_command_infinite_loops' into updates_app

Conflicts:
	kalite/main/management/commands/subtitledownload.py
	kalite/main/management/commands/videodownload.py
	kalite/templates/video_download.html
fixing bugs by removing commented out variable setting