initial DB-based logging of unregistered devices.  Will give us some idea of what's up
extending logic to visiting the registration page
Merge branch 'release-0.10' of github.com:learningequality/ka-lite into central_server_stats

Conflicts:
	kalite/securesync/devices/api_views.py
	kalite/securesync/engine/api_views.py
adding comments, more robust checking for remote IP, adding missing import
fixed bug on tuple output, and mis-referenced field
Merge pull request #616 from bcipolli/central_server_stats

initial DB-based logging of unregistered devices