Fixed all common and LMS tests.

The tests were failing because XMLDescriptor adds in some attributes
to _model_data, such as `xml_attributes`, that aren't necessary. The
solution is to handle all XML parsing in VideoDescriptor. There's
still one test failing in CMS, which has to do with metadata being
saved. I'm still working out how to update it in such a way that it
doesn't fail, but still tests something meaningful.

Feature/cdodge/convert to portable links on import and clone

Fix jumping to the top of the page on unit delete.

add a few debug messages to get localhost debug information. Also partition out the MongoDjangoToolbar configuration into a separate env config. This is because doing imports on large courses grinds localdev to a halt due to all the stack trace generation.

add another test. Seems like we never had an explicit test on an import into a new course-id. This fixes that

also support a link rewriting on course import and clone for the following format /courses/[org]/[course]/[run]/. We just need to substitute in the new course-id.

add ability to rewrite links on the old /courses/<org>/<course>/<run>/jump_to/i4x://&lt;org&gt;/&lt;course> .. intracourseware linking to the new portable /jump_to_id/<id> format

changing http:// to // on intro video urls

Upgrade diff-cover to newest version

Jonahstanley/fix courseteam tests

Fix enroll-multiple button

Feanil/master with release

make template string unicode

Add cronjob analytics to instructor dashbaord

Update the XBlock version to fix save bugs

give some debug message regarding why export has failed