Reorganize information in CONTRIBUTING.rst, link to ReadTheDocs
wordsmithing
When sending bulk email check if course is authorized.
Also the idash_mode property is stored seperately for each course.

LMS-2565
Remove email field from CS client user object

This requires cs_comments_service commit 1d50176.
Do not show "View in Studio" links for child verticals of verticals.

STUD-1558
Show error page templates
Expose "enabled" checkbox in Embargo admin
Drag and drop on container page.

STUD-1309
dnd container page styling
Switch the container page to use the new view
Restore the ability to drag at any level inside a vertical and clean up templates.
Update unit test based on changes in master.
fix authentication check in auth
add logging to course import
pep8/pylint cleanup
Merge pull request #3580 from edx/sarina/show-enabled-checkbox

Expose "enabled" checkbox in Embargo admin
Adds very basic about page style to ul, ol and dl

About pages need basic support for lists since professors often want to display lists or 'definitions'
fix for Studio 404 and 500 page layouts
STUD-864
Only show drag handles in draft mode
Bok choy acceptance test for drag and drop.