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.
Merge pull request #2517 from ionis-education-group/remove-video-autoplay

Remove autoplay for video in course about page
Reformatted event type info to get it out of wide tables
Merge pull request #2800 from edx/ahodges/documentation/reformatevents

Reformatted event type info to get it out of wide tables
Use display_name_with_default instead of display_name.
Increase max-width for breadcrumb trail.
Improve code clarity.
Merge pull request #2807 from edx/christina/containers

Support xblocks with children on the container page.
Fixes tinymce bug:
    On using the image plugin, the image was not appearing in the
    visual editor immediately after using the command.

    Selenium test added.
making mixed ms capable of front ending all modulestores for most operations including CRUD
STUD-600
Mixed no longer translates
unicode correctly and understandably
Pass user id to update_item
Point to prefer_xmodules new locn
Better sorting of stores for get_courses
May apply to all store ordering
Mixed modulestore handles most modulestore functions, cont.
Change get_courses default branch to draft.
We need to figure out how apps configure what default they want or ensure they get the one they want
No longer create loc maps on create_(item|course)
pylint and pep8 fixes
Test exception on read-only db