initial implementation, using hacky database way
removed pdb; added logging info; renamed template var to video_exist; removed extra char from template
implemented direct filesystem method for accessing video counts, use by default
tweaking UI to be a bit more reasonable for found videos
Migrating model syncing to a (static) class, rather than flat functions shared through settings.py
Migrating model syncing to a (static) class, rather than flat functions shared through settings.py.  Similar for device_counting.
Merge branch 'syncing_models' of github.com:bcipolli/ka-lite into syncing_models

Conflicts:
	kalite/securesync/models.py
moving api urls from url to api_urls, like in main.  Separating translatable strings
removing debug code, adding code comment
when retrypurgatory fails, it should output to stderr.  also adding a few more translatable strings
Merge branch 'api_url' of github.com:bcipolli/ka-lite into api_url
only expose admin on distributed server under debug mode.  Note: still accessible by /admin, we can say so in the docs.
reconfiguring landing page (add install nav, remove sign up nav, switch button rows); change homepage title
move analytics to central only, and give a clearer (non-admin) name.  Add starting admin info
Merge remote-tracking branch 'origin/urls' into admin_debugonly
easyadmin provides links to offline help and online docs, as well as a WARNING link to the Django admin
moved stats from admin to a separate page; fixed a couple of small admin bugs, made everything translatable
updated title
fixing bug in central server link
automatic creation of org and zone from registration form