TNL-884

This commit puts a limit on the size of files that
course staff can upload to MongoDB. The limit is
enforced on the frontend in javascript as well
as backend via the /upload endpoint.

The limit is hard-coded in cms/envs/common.py and
may be changed according to the user's custom
needs.

If the user tries to upload a file that's too
large, an error message will pop up, with a
customizable url that pointing the user to an
external page with an alternate upload procedure.
This url is specified im cms/envs/common.py.
If not set, this url will not be displayed.

TNL-649

TNL-683

TNL-138

TNL-291

TNL-554

TNL-163

This test is failing in a different test environment (Solano) because
the built html has reversed the order of the width and height attributes
from what we are expecting. This change focuses the assertion to the
pieces that are important (as noted in the unchanged comment above
the assertion).

STUD-2017

This commit adds validation for course advanced settings. Currently when course
administrators make invalid changes in the Settings/Advanced Settings tab,
they're not notified through a new modal window of the list of invalid settings
changes.

* Extending CourseMetadata
    - Previously, we only had update_from_json method in CourseMetadata.py,
      and it was only validating one field every POST request.
    - Now we have validate_and_update_from_json method that encapsulates the
      functionality of update_from_json into a validation call
    - To avoid discrepancy of validation standards between modules, validation
      uses the from_json method implemented to each field in xblock.

* Different Response in advanced settings ajax requests
    - After receiving a POST ajax request, course.py calls
      validate_and_update_from_json, and sends a json object of either:
        1) valid course metadata model
        2) error objects

* Error Messages shown in validation-error-modal
    - error objects passed through ajax are shown in a separate modal.

TNL-56

TNL-46

I've changed Studio to catch JavaScript errors when rendering xblocks, log the error, but to then continue as normal. This means that the user is still able to interact with the xblock to delete, duplicate etc. This seems reasonable as the xblock is only rendered as a WYSIWYG representation so if it isn't fully interactive that shouldn't be a big problem.

Studio: adding course re-run-centric static template rendering

* initial HTML for dashboard states
* initial HTML for new course re-run view/form
* initial HTML placeholder for outline alert UI

Conflicts:
	cms/templates/index.html

Studio: adding styling for course re-run-centric views

* adding new view/page mast-wizard type
* refactoring create course/element form styling
* adding course re-run view specific styling
* adding courses processing styling (w/ alerts and status)

Course rerun server-side updates: support display_name and DuplicateCourseError.

Studio: further design revisions and tweaks from feedback

* removing new window attribute from re-run control
* removing links from processing courses
* revising look/feel of dismiss action on dashboard + alert
* correcting font-weight of dashboard processing title
* adding extra space to course rerun action on dashboard
* re-wording secondary cancel action on rerun view

Conflicts:
	cms/templates/index.html

Added interation on unsucceeded courses in dashboard

Studio: removing 'rel=external' property from course re-run actions

Studio: removing hover styles for processing courses

Fixed value bug in split and set course listing to display run

moved task.py for rerun