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.
missed rst
further explanation on entry_points
add infinity symbol to calc preview
Fix URLs for static resources
Display only the first component name in the page (and nav) title.
STUD-1351
adding in gray versions of social icons for use in new email template. Using new name to ensure old links and existing emails using older templates still stay active
Move FieldDataCache assert to check both get and get_or_create
Upgrade CodeMirror to 3.21.0 (with accessibility changes from
http://bgrins.github.io/codemirror-accessible/)
LMS-1802
adjusted color of russian social network image to be a lighter gray
Add logging to embargo middleware
Add map to problem_check event with descriptions of student answers

The map contains a human readable description of the answer if
necessary. It is useful for problem like multiple choice, when the
response of the student is replaced by a moniker. For example "choice_0"
instead of the full text.

Fixes: AN-587
Update translations (autogenerated message)
Merge pull request #2782 from edx/sarina/030314-language-update

Update translations (autogenerated message)
Remove assert stmt from i18n validate script
Increases precision of percentages shown in 'Total' bar on the progress page.

The percentages shown currently can be confusing. For example, if the true weight
of a category is 0.76925% and the student scores 100% in it, they will see '0.8%
out of a possible 1.0%'. Increasing the precision to 2 decimal places changes it
to '0.77% of a possible 0.77%'.

LMS-2205
Continue showing edit dialog until saving is complete to allow user to correct validation errors.
Removed all Push mode information

We should only support Pull mode

stud-1332
Edits from review

stud-1332
Import BrokenPromise