Quadrant view for scatter plot coach-report.
Added comments.
Adding LOGIN_URL and LOGOUT_URL; needed for login_required header.

Conflicts:
	kalite/distributed/settings.py
Wrap interface text in gettext.
Merge pull request #1725 from rtibbles/coach_report_crazy

Quadrant view for scatter plot coach-report
Merge pull request #1730 from bcipolli/securesync-login

Fix registration template permissions
Merge branch 'develop' of github.com:learningequality/ka-lite into static-refactoring