Merge pull request #3562 from caesar2164/giulio/zoom-image-firefox-bugfix

Fixes firefox image hidden overflow bug.
Update drag and drop documentation
Merge pull request #3559 from edx/sylvia/docs/DOC-99

Update drag and drop documentation
Merge pull request #3417 from edx/usman/lms2518-refund-emails

Parameter from_email to send_mail() should be string
Merge pull request #3575 from edx/markhoeber/documentation/fix-link-in-readme

Fixed link to docs.edx.org in readme
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
Create edx remote if it doesn't exist
Include author in table
IGNORED_EMAILS is no longer used