caveat: with a bit of hackery.  Need to do better testing once things are live.

- we don't use it, and if we do want to change the arch, we should have a proper central user info service.

- this may not be a good idea, but needed for testing cohorts for now...

- Create new cohorts.py file
- moved code there from models.py
- implemented necessary functions.

Next: testing :)

- still needs style, more features, but basic functionality works

- lets user see and add cohorts
- needs styling
- needs to allow them to actually manage membership!

fix cohorts in create, and read, and update regular expressions to fix courses with periods not working in General commentable

Toggling of code should mark editor as dirty.

Do not run the lms jasmine tests on jenkins for now, until we fix them.

Fix/cdodge/remove hide progress tab

Feature/cale/fix staff debug link