MA-1061 Fix IntegrityError caused by race condition in CourseOverview.get_from_id

Update the version of django-staticfiles

OSPR-535 Partial Credit

This gets us:

- Static files can have non-ASCII characters in them.
- A useful log message if a file can't be found.

mattdrayer/SOL-981: Integrate edx-organizations application

Squashed commit of the following:

commit 0f7c2af5f7b8caed575dd253a45299293b2729d7
Author: Colin-Fredericks <colin.fredericks@gmail.com>
Date:   Tue Jun 30 12:04:43 2015 -0400

    Forgot icon

commit b48970392741130f774709c54eb6e5ab0089812c
Author: Colin-Fredericks <colin.fredericks@gmail.com>
Date:   Tue Jun 30 11:49:57 2015 -0400

    OSPR-535 Partial Credit

    Squashed commit of the following:

    commit 6dd34f58f994e32d0d54bf1d67bffd04e0f8ef08
    Author: Colin-Fredericks <cof945@dhcp-140-247-184-176.fas.harvard.edu>
    Date:   Tue Jun 30 11:44:01 2015 -0400

        Fixing accidental overwrite.

    commit 1ff8fc4b0e83b90356e8e8dce1022f49bfd162cf
    Author: Colin-Fredericks <cof945@dhcp-140-247-184-176.fas.harvard.edu>
    Date:   Tue Jun 30 11:18:36 2015 -0400

        OSPR-535 Partial Credit

        Revised after first pull discussion.

Fixing scss typos

Fixing check/x display problem

Empty set is not []

Shuffling empty answer code to grade properly.

I don't think I ever wrote this in the first place...

Adding tests for MC and Checkbox

including proper partial-credit marking and scoring

Numerical and OptionResponse tests

Also a few improvements to NumericalResponse problem type and
exception-raising.

CustomResponse tests and more numerical tests

Increasing coverage and fixing typos

Exception added for pylint false positive

Hopefully fixing coverage issue

Retabulating line continuation

Bok Choy test for partial credit

Copypasta fix

Adding tooltip for partial credit

Improving and expanding comments

Minor fixes

* asadiqbal08/SOL-1058: Add edx-organizations to certificate web view
  * Support organization logo asset management
  * Remove organization fields from Studio certificate configuration model

* SOL-981 pull request feedback fixes

Handle case of video in a content library with no transcripts.

Remove signal_handler conditionals in BulkOperationMixin

Fix IE10 issue with delete button.

Fixing course settings page for change in minimum grade

Additional configuration options for LTI provider feature.

Separate out the Backbone image field

Remove Stanford branding from external_auth view

Update i18n-tools [LOC-88]

We're already running a version of this, with the default Stanford
address removed, so the community shouldn't be running it either.

Update edx reverification block on plateform

This partially addresses TNL-1776

Ensure that discussion admins can delete team posts.

Update translations (autogenerated message)

Christina/less assets

Slashes in Asset Displayname cause `export` to fail

Add Full Country & Language Names to Teams

Delete button should not be clickable if in use by a unit.

No need to install prereqs twice on circleci.com

Improve client-side performance.

TNL-2945

TNL-2669

Add Bok Choy tests for URL routing on teams page.