Revert accidental push of changes to master

Video tests fix

updating mktg defaults in common.py

This reverts commit e9c5d765, reversing
changes made to 5ff9f3be.

read MKTG_URLS from env.json

Skip a test that is causing intermittent failures due to the way it is ordered.

Will/fix rake test

Removed cleaning of reports folders, since this was
interferring with coverage reports generated
sequentially by rake test.

Developer-private settings files

Developers can have private settings files by creating
lms/envs/private.py or cms/envs/private.py.  They are imported
at the end of dev.py.  Note that they won't be imported if you
are using one of the other dev*.py variants.

Re-insert "if in course" check for displaying paragraph about forums.

Accidentally got removed in pull request 13.

Will/diff cover integration

[STUD-244] add exporting of 'about' content as well as adding unit test checks

seems like there's a Django bug and the SESSION_COOKIE_NAME needs to be ...

LMS theming for Stanford 6/11/13 launch

theming - revised variables and link/button styling to account for edX's registration and login constrast/styling changes

Minor stylistic tweak.

Rather than require the `PLATFORM_NAME` to be specified in the
`ENV_TOKENS`, allow the default setting in `common.py` to be used.

Themes do not necessarily want all of the available LMS routes, such
as `/jobs` and `/university_profiles`. This change splits up the
`lms/urls.py` file and selectively enables/disables routes based on
whether or not a theme is enabled. This is a naive solution for now;
a better solution gives themes a way to selectively overrides such
routes.

Additionally, with the `MKTG_URL_LINK_MAP` setting that hits certain
routes immediately on each page render (whenever the `marketing_link`
helper function is called), themes may crash if they don't leave
all marketing link routes present in `lms/urls.py`. This change also
provides the ability to override the `MKTG_URL_LINK_MAP` in the
settings.

Finally, modify the mitxmako marketing URL middleware to not try to
reverse disabled URLs, which are those keys in the map whose values
are `None`.

Just as is done with the main LMS application.scss file, rewrite the
course.scss file with Mako to conditionally import a theme's
variables overrides. Add the course.scss file to the list of ignored
Git files so that it doesn't keep getting committed over and over
again.

This also requires us to add a hardcoded line in the assets Rakefile
for the moment, so that the course.scss.mako file gets properly
preprocessed. Once the preprocessing is done by a Django management
command, we won't have to do this anymore.

Since the theme Sass is just a simple variables overrides (for the
moment), it must be imported right after the default variables Sass
file (if at all). At the bottom of the file, it has no effect.