Moved student management functions under securesync/users.

Fixed issues with endpoints and rendering of userlist.
Move userlist functionality inside securesync app.
Fix for translation issue in matching "Ungrouped" for userlist.
Include moved facility_user_management.js
for youtube-dl, download to a temporary dir before moving to content/
make the temp directory persistent throughout multiple scrape_video calls
moving shared/videos into updates
Merge branch 'develop' into userlist_fix_api

Conflicts:
	kalite/main/views.py
	kalite/updates/views.py
fix call to setGetParam for set_server_language
respect --no-ka-trans and --no-kalite-trans parameters
Fix for #1496 - don't give a 404 on a request for local device information\!
download directly to the content/ dir
Merge pull request #1520 from aronasorman/1456

for youtube-dl, download to a temporary dir before moving to content/
Merge pull request #1516 from rtibbles/userlist_fix_api

Fix endpoints for userlist management and move userlist management inside the securesync app
Merge branch 'develop' of github.com:learningequality/ka-lite into eliminate-shared