* add a days_early_for_beta inherited policy option
* students in the beta_testers_{COURSE} group get to see content that many days early
* Clean up some docstrings related to time formats
* Add basic test

just tickle a file to for build cms-master. I dont seem to have the rights to force a jenkins build.

- also updated some out-of-date docs

This reverts commit 793354a0.

- needed for cert generation (and later lots of other things)

Add discussion tag

* still needs better error checking and testing

* specify in tabs list in course policy
  - active page tracking now done in tabs.py
  - properly handle the fact that there may be multiple textbooks

* Still need:
  - wiki pages
  - (if that's delayed, special-case syllabus support)

loaded into the page in a data attribute instead of loaded on request via ajax.
The user profile page also does not provide facilities for adding
comments/responses, which I think would clutter the page too much.

Also removed some unused stuff from views.py.

course id for seed_permissions_roles, and also the script itself to tell you that.