Make sure temporary course directory uses safe characters.
Only permit ascii characters in filenames generated from course_ids.
Don't show cohort information when disabled

TNL-552
Address code review comments
Minor cleanups
Performance enhancements for unit tests
in test_contentstore, don't load the xml course if not necessary
Upgrade pymongo
LMS-11437
Test multiple threads linear growth
Remove unused credentials from mongo init
was breaking pymongo 2.7
tz aware
Merge pull request #5517 from edx/brian/fix_export_course

Make sure temporary course directory uses safe characters.
Merge pull request #5501 from edx/andya/disable-cohorts-ui-bug

Don't show cohort information when disabled
Small changes to the segment.io event handler
Updates 10-7 release notes
Merge pull request #5537 from edx/sylvia/docs/relnotes10-7

Updates 10-7 release notes
Merge pull request #5527 from mulby/tweak-segment-io-endpoint

Small changes to the segment.io event handler
Make unit tests work on older mongo versions
Consistently ensure dog_stats_api tags are formatted correctly
Move JavaScript from dashboard template into its own module
Make HTML comments Mako comments
Added handling in gitlog for missing import logs

Fixes a template error that occurs when viewing a course's detailed
git import log. The problem happens for courses imported using methods
other than the `git_add_course` command.