Ccp0101/capa pythonpath

Allows for additional paths when executing code in a loncapa problem. Adds a default path of data/course/code.

Add fixes to notes in #182

* use 'location' instead of 'id' in views.
* still need to change names in the coffeescript--quick fix didn't work

Victor/cms more auth

* add optional author_str param to export_to_github
* pass the django user info to that param

* add dummy has_access(user, location) method
* re-organize views by type of access checking needed.

* connect up views from student app
* Add initial @login_required decorators on the protected views
* Add tests for some of the basic functionality

CodeResponse for external/queued grading of student code

Victor/cms auth

cleans up home page header design, adds social sharing to header, adds tos, privacy policy, honor code, help and copyright pages, add liks to those pages in footer, finished contact page

adds pressrelease page, breaks about content into seperate pages, imporvoves some visual elements of about and jobs pages