Skipped 'print' statement violations, as print() is Py3k syntax.

TNL2159

STUD-1726

[LMS-2757]

This commit adds all of cms.

These keys are now objects with a limited interface, and the particular
internal representation is managed by the data storage layer (the
modulestore).

For the LMS, there should be no outward-facing changes to the system.
The keys are, for now, a change to internal representation only. For
Studio, the new serialized form of the keys is used in urls, to allow
for further migration in the future.

Co-Author: Andy Armstrong <andya@edx.org>
Co-Author: Christina Roberts <christina@edx.org>
Co-Author: David Baumgold <db@edx.org>
Co-Author: Diana Huang <dkh@edx.org>
Co-Author: Don Mitchell <dmitchell@edx.org>
Co-Author: Julia Hansbrough <julia@edx.org>
Co-Author: Nimisha Asthagiri <nasthagiri@edx.org>
Co-Author: Sarina Canelake <sarina@edx.org>

[LMS-2370]

Fixed grading tests

Version numbers have very different ranges for different browsers so not having a dictionary of those.

Fixed a whitespace issue

Fixed pylint/pep8 violations

Don't need django_url

Spacing issues

Changed how commenting works

Forgot one

Used wrong name

Changed around importing

Remove django_url

Fixed function orderingn

Made logic nicer for getting a new browser

Modifying tests to run in opera

Needed to increase time to account for slow sauce loading

Now safari LMS works

Forgot an assert statement

Skipping a few tests for opera

Rather than asynchronously saving when a setting is updated, we now
prompt the user to confirm their changes and only persist the data if
they hit the save button. Lettuce tests are updated to expect this
behavior and some new ones are added.

This works like css_click in that it will retry if there was a stale element reference exception

Please note that 2 tests will not reliably work:
Deleting a grade- Was able to circumvent this with javascript
Moving the grade slider- Could not circumvent, is skipped but the framework is in place