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 'release-0.10' of github.com:learningequality/ka-lite into avoid_command_infinite_loops

Conflicts:
	kalite/main/management/commands/subtitledownload.py
	kalite/main/management/commands/videodownload.py
	kalite/templates/video_download.html
removing buttons
necessary to get coach reports working on central server.
Merge pull request #526 from bcipolli/no_cp_buttons

Limping in to the finish line... remove non-functioning buttons from control panel (and fix central server coach reports!)
Merge branch 'release-0.10' of github.com:learningequality/ka-lite into force_sync
expose a simple endpoint for launching syncmodels, expose a button for launcing that API endpoint
moving button to easy_admin page, fixing debug-only class
slightly better UI with no extra div
Redo of most of PR #530, without the cruft.
Manually applied changes from PR#3@jamalex.
Added cute images back in, for @bcipolli.
Updated topic tree data, with partner content excluded.
Merge branch 'release-0.10' of github.com:learningequality/ka-lite into release-idoc
Merge commit '3fbf1886b5ffec93c45329c8628eeeff1f27bfa4' into HEAD

Conflicts:
	.gitignore
Khanload now deletes exercises due to missing file, not missing old entry.
Styling fixes on the exercise pages.
Tweaks to khanload command, added a few exercises to blacklist.