Text changes for Email Sent by addition
A better check for the existence of matlabinput element.
Outline for release notes
Removed grading and drag'n'drop
release notes tweaks
Make sure that the currently-set language is the
one that shows on the left sidebar if no language
preference exists.

ECOM-135
Use opaque_keys w/ model vars not parsing of url
to generate url.
LMS-11209
JS regex's need to escape special chars
LMS-11260
Pin coffee-script version to 1.6.1.
BLD-1226: enable 'delete_inactive_group' test.
Merge pull request #4970 from edx/anton/enable-bok-choy-test

Enable Bok Choy split test.
add tests for drag and drop unit into collapsed subsection on course outline page
update/cleanup code + move verify_ordering and drag method to studio utils
Add test for at least one group before saving a group configuration
Merge pull request #4959 from edx/diana/set-cur-lang

Make sure that the currently-set language is the one that shows on the left sidebar if no language  preference exists.
Merge pull request #4973 from edx/tim/single-group-is-ok

Update test_group_configuration_validation on single group allowed
Merge pull request #4969 from edx/benp/fix-js-tests

Pin coffee-script version to 1.6.1.

1.6.3 is causing some issues.
login, registration, and dashboard page changes for third-party auth
Facebook auth support.
doc-byte-sized-tasks: Add link to the byte-sized tasks in CONTRIBUTING

Thanks to @adampalay, we now have a list of byte-sized tasks, which are
useful for new contributors who want a gentle introduction to the
platform. This PR adds a link to the tasks tagged as byte-sized in the
public tracker.