Updates to Demographics Display

- Gating on feature enabled for Open edX users
- If feature disabled and Insights URL is set, displaying message pointing users to Insights
Fixes for MOB-836 and MOB-766 and MA-96.
Studio: cleaning up/removing unused sass

* removing unused font-family-centric Sass variables
* removing unused graphic images and Sass references
* clean up of style removal fallout
deleting more things
Add the ability for course staff to specify a Survey and make it required so that a student must fill it out before starting the course
Remove extra large-FOO-icon.png files
Removed more files from cms
Deleted some unused images under common
content-types is no longer around
re-add search-icon.png
Merge pull request #5799 from edx/hotfix_candidate/2014-10-30

Merging Hotfix candidate/2014 10 30 as per release process
Add warning about sensitive info in course export

DOC-977/DOC-991
Merge pull request #5818 from edx/release

Merging latest updates to release
Update change log for export security warning

DOC-977
Ignore errors during cleanup of course export command.
Merge pull request #5811 from edx/carol/docs/DOC-977

Add warning about sensitive info in course export
Merge pull request #5820 from rocha/dont-raise-error-on-course-export-command-cleanup

Ignore errors during cleanup of course export command.
fix click event for actual target
TNL-138
Merge pull request #5782 from edx/remove-analytics-demographics

Updates to Demographics Display
Merge pull request #5808 from edx/zub/bugfix/tnl-138-createunitthrowserror

fix click event for actual target