Cleanup pep8 violations in test_correctmap.py

Initialize MakoMiddleware manually during certificate grading runs.

Without this, problems fail to load because they can't find how to
render themselves, and the certificate generation grading run will
get an inaccurately low count of the possible points a user could
get (anything they didn't see will be omitted), inflating their
grade during certificate calculation and making it inconsistent
with their Progress page.

Clean up assets page notifications

Remove hack to work around multiple notification click issues -- and actually resolve
the issue so that the hack isn't necessary

Fix test_system looking like a test to nosetest. Fix class inheritance causing double counting of coverage.

Instrument sequentials with segment-io

Refactor Backbone notifications

pep8 changes made during long refactoring

Fix a bug in diff-cover

Feature/brian/regrade celery 2

Conflicts:
	AUTHORS
	common/lib/xmodule/xmodule/tests/test_annotatable_module.py
	common/lib/xmodule/xmodule/tests/test_capa_module.py
	common/lib/xmodule/xmodule/tests/test_combined_open_ended.py
	common/lib/xmodule/xmodule/tests/test_conditional.py
	common/lib/xmodule/xmodule/tests/test_html_module.py
	common/lib/xmodule/xmodule/tests/test_progress.py
	common/lib/xmodule/xmodule/tests/test_xml_module.py
	lms/djangoapps/courseware/tests/__init__.py

Cherry pick change to url matching regular expression. Fixes LMS-37

remove assets.js from the PIPELINE_JS since it seems to cause that file ...

When changing variable names for code review critique, accidental cut/paste prevented intended behavior.

Fix a few remaining tz naive dates