first pass, through Django
refactoring code into (optional) settings
forgot migration file.
fixing username / user bugs
workaround for new users; better fix to come\!
invalidating cache when settings change.
Merge branch 'release-0.10' of github.com:learningequality/ka-lite into local_password_hashes

Conflicts:
	kalite/settings.py
Merge branch 'release-0.10' of github.com:learningequality/ka-lite into local_password_hashes
refactoring for cleaner implementation, better validation.
clean up control panel queries
removing the static, disk-based node cache.
update queries to be more efficient
Merge branch 'release-0.10' of github.com:learningequality/ka-lite into efficient_facility_usage

Conflicts:
	kalite/control_panel/views.py
small bugfixes to correct facility usage page.
Merge branch 'local_password_hashes' of github.com:bcipolli/ka-lite into release-idoc

Conflicts:
	kalite/securesync/users/views.py
Merge branch 'efficient_facility_usage' of github.com:bcipolli/ka-lite into release-idoc
Merge branch 'remove_node_cache' of github.com:bcipolli/ka-lite into release-idoc
Merge branch 'efficient_student_view' of github.com:bcipolli/ka-lite into release-idoc

Conflicts:
	kalite/coachreports/views.py
do not call sign() directly
adding comments, returning better message on unexpected error