Generalize assets to any block_type but using
AssetKey and the metadata store
PLAT-204
Merge pull request #5847 from edx/dhm/generalize_assets

Generalize assets to any block_type but using
Skip test broken on master. Sent to team for review.
Merge pull request #5865 from edx/benp/skip-broken-MA-117

Skip test broken on master. Sent to team for review.
Fix broken test (due to merge conflict).
Rename Studio logo

OPEN-301
add logging for cybersource errors; fix minor unicode bug
Merge pull request #5867 from edx/mobile/fix-broken-master

Fix mobile_api broken test (due to merge conflict).
Add a `created` field to OrderItem.
Remove multi-threading test as unnecessary and flakey
also fix other users of check_mongo_calls to use None if they don't care about sends
PLAT-239
Merge pull request #5868 from edx/diana/add-created-to-orderitem

Add a `created_at` field to OrderItem.
Merge pull request #5871 from edx/dhm/remove_test

Remove multi-threading test as unnecessary and flakey
Merge pull request #5841 from edx/cms-consistent-branding-image-names

Rename Studio logo
Merge pull request #5869 from edx/adam/unicode-fix

add logging for cybersource errors; fix minor unicode bug
Display validation messages for any xblock on the container page.

TNL-683
Studio: revising element-level xblock information styling
Studio: revising xblock validation message list styling
Merge pull request #5710 from edx/christina/general-component-errors

Support validation messages for any xblock (on container page).
Merge pull request #5873 from edx/release

Release
Implements keyword sub feature for bulk emails

This commit pulls in changes from #4487 that implements keyword
substitution for bulk emails. With these changes, an instructor can
include keywords in their bulk emails which will be automatically substituted
with the corresponding value for the recepient of the email. Keywords are
of the form %%keyword%%, and the keywords implemented in this commit include:

%%USER_ID%% => anonymous_user_id
%%USER_FULLNAME%% => user profile name
%%COURSE_DISPLAY_NAME%% => display name of the course
%%COURSE_END_DATE%% => end date of the course

Client-side validations have also been implemented to ensure that only emails
with well-formed keywords can be sent.
The architecture is designed such that adding in new keywords in the future
would be relatively straight-forward.