Convert course team management to new URL scheme.

Things to test:

1) Course team management works (adding, deleting, making admin).
2) Links to Course team page works (on each settings page in RHS bar, from checklists).
3) Auto-enrolling of course team members works (View Live works).
4) Course creator request works.

@singingwolfboy @dmitchell Please review (and check out the branch and test it!)

Note that I did NOT change the index and course_creator_request methods. Those looked "RESFful" enough to me. I moved course_creator_request down to the "new" section in urls.py. index was already there. Deleted listing, which duplicated index.