Remove autoplay for video in course about page

The iframe was generated with autoplay=1, which, sometimes, would cause
the video to play in the background.
fix non-microsite SUBDOMAIN_BRANDING defaults
missed rst
add infinity symbol to calc preview
Make staff view work w/ pure xblocks (that only have a descriptor system)
Fix strings to avoid dangling commas
Internal/External Studio file URLs

- Changed link URL of file name to use public/LMS url
- Added toggle link to display all public URLs for instructor convenience
The correct LTI keyword is "roles", not "role"

This is only a correction in the documentation
add new feature to make sure we aren't writing PII into the application logs. So far we're aware of doing so regarding Auth use-cases
Add module display name to module related server events

This information will likely be used frequently for analytics purposes, so we would like to denormalize here to avoid having to join with the modulestore later.

Fixes: AN-594
Merge pull request #2696 from mulby/gabe/add-problem-name-to-events

Add module display name to module related server events
Variable-ize "Certificate of Achievement" text
Merge pull request #2551 from edx/giulio/custom_cert_names

Variable-ize "Certificate of Achievement" text
Also clean up the 3rd-party po files.
Generate now removes format flags.
Add test of local_resource_url in AcidBlock
Add tests of more scopes in student_view
Mark xblock initialization status using css class (in part to make testing easier)
Remove doc-ready tests, which were flaky
Updated po/mo files without format flags.