Avoid queries unless needed.
Move "status" to main app; securesync should not have dependencies on KA data
Fixing import bug, reducing queries for teachers.
Merge branch 'develop' of github.com:learningequality/ka-lite into minimize_queries_2

Conflicts:
	kalite/main/api_views.py
Merge pull request #818 from bcipolli/minimize_queries_2

Minimize queries 2