This reverts commit b8184d18.

[second attempt which addresses bug building Studio]

This reverts commit 1d6fceda.

Respond to review comments:

- Rename build and config files for consistency between lms/studio.
- Fix merge conflicts with lms require config.
- Devstack uses optimized pipeline to skip require JS optimizer step
- Add tests for render_require_js_path_overrides

Several IE bugs have been fixed in 2.4.

Co-Authored-By: Jean-Michel Claus <jmc@edx.org>
Co-Authored-By: Brian Talbot <btalbot@edx.org>
Co-Authored-By: Tim Babych <tim@edx.org>
Co-Authored-By: Oleg Marshev <oleg@edx.org>
Co-Authored-By: Chris Rodriguez <crodriguez@edx.org>

[PLAT-217]

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.