Conflicts:
	common/lib/xmodule/xmodule/course_module.py
	common/lib/xmodule/xmodule/modulestore/mongo.py
	common/lib/xmodule/xmodule/modulestore/search.py
	common/lib/xmodule/xmodule/modulestore/xml.py
	doc/development.md
	lms/envs/common.py

studio - changed expectation of lettuce test for course overview toggle

need to add the depth parameter to the DraftMongoStore   implementation ...

Handle metadata from save being empty

Decrease the number of queries needed for LMS courseware

Cheat sheet for heading and explanation.

explanation markdown

Peer Grading Interface

Add BDD lettuce tests for studio overview toggle section feature.

for code review issues

Add property to course module to check if a course is new

The property can be set in the policy metadata. If it is not specified
then it is set to true if the course has not started yet.

Also adds a property to check how many days are left until the course starts.

the parent directory might not already exist, so we have to call makedir...

the parent directory might not already exist, so we have to call makedir with recursive=true to auto-create any parent folders

Catch ItemNotFound errors at the top of get_module, rather than in get_module_for_descriptor, to maintain previous LMS behavior

Feature/cas/speed editor

This cuts the number of queries in 6.002 courseware loads from ~650 to
~5-40. Still to do: cache CustomTag templates so that we only load them
once per request.

make sure we commit the course module first when importing. There's a sn...