- Rename escape_json_dumps to dump_js_escaped_json
- Rename escape_js_string to js_escaped_string
- Update js_escaped_string to output empty string for None
- Introduce dump_html_escaped_json
- Move dump_js_escaped_json after the pipe as new best practice
- Introduce additional uses of helpers
- Introduce new djangolib directory and move js_utils

Make escaping for json simpler and more consistent in Mako templates
- add escape_json_dumps to escape and json.dumps
- add escape_js_str to escape javascript string
- refactor Studio to use escape_json_dumps in Mako templates

TNL-2646: Escape json.dumps

This reverts commit 2bfbda3c.

This reverts commit c94abd27.

This reverts commit c94abd27.

This is a public, versioned, RESTful API for importing and
exporting full course content. The code was initially ripped from the
existing import/export API in the CMS contentstore djangoapp and wrapped
in Django Rest Framework view classes. It's a new djangoapp in
the openedx directory which is largely an abstraction off the CMS
Import/Export views.

This PR includes configuration changes. Most notably, Studio is
configured to serve the OAuth2 provider alongside the LMS.

This is the initial thread on the code list:
https://groups.google.com/forum/#!msg/edx-code/DmnHWmly25A/ZqjD1zb4o7oJ

And this thread contains another description of the changes:
https://groups.google.com/d/msg/edx-code/6dP9SEKsmqQ/Pvyn8fBDx68J

There are a numerous non-covered lines, all of which are missing
coverage in the CMS API this was ported from. They're mostly error
conditions, such as handling of multipart file upload errors.

TNL-925

Located in ```howitworks.html``` and ```import.html```.

* updating vendor files
* updating class syntax (to new FA-based classes) for all UI elements
* correcting broken tests

STUDIO_NAME = "edX Studio"
STUDIO_SHORT_NAME = "Studio"

For theming and internationalization

STUD-2017

Changed help button to link and removed drop-down items

STUD-1283

Reviewed and updated all on-page panel help text in Studio for clarity,
consistency, and brevity.  Updated template HTML files to change text

STUD-924

    And fixes for rebase-breakage.

Studio: adds in instructional copy to user on when it is safe to leave the import view without harming an import process

Studio: revises import help/status copy to better reflect/generalize what is done with imported content

Add test cases for import status