Fixes display of time in thumbnails, need to target...

...specific browsers with some additional CSS

	modified:   main/templates/exams/videotest.css
Merge branch 'master' of https://github.com/Stanford-Online/class2go into wescott-master-exercise-work
Merge branch 'master' of https://github.com/Stanford-Online/class2go into wescott-master-exercise-work
Make static pages use ContentGroup.groupinfo_by_id
Correctly show parent when editing exam

* Correctly display the parent on the exam edit dialog for child exams.
  (closes #1825)
  (closes #1914)
Fix return type of create_exam's prefill_children

* Addressing comments on PR #1918, fixing the return type of
  prefill_children and it's call signature in more places.
* Also cleans up some validation errors in create_exam.html
Merge branch 'master' of https://github.com/Stanford-Online/class2go into wescott-master-exercise-work
vidya-master-create-exam populating grace period and hard deadline after due date is set
closes #1935 staff 500 page
styling fix for 500 pg
WIP doing email stacktrace
20 minute cache leftnav
Merge pull request #1938 from Stanford-Online/jbau-20min-leftnav

20 minute cache leftnav
make sure that the stacktrace gets logged and sent
Merge pull request #1918 from Stanford-Online/jrbl-1825-editing_exams_keep_contentgroup

Jrbl 1825 editing exams keep contentgroup
upstart script to ensure /mnt perms are right (#1648)
celery workers should scale with cpu's (#1944)
/mnt perms: remove old code for creating /mnt in chef (#1648)
/mnt perms: make sure to create dir (#1648)
Merge branch 'sef-1648-mnt-perms' of https://github.com/Stanford-Online/class2go into sef-1648-mnt-perms