adding a little ux to the download video and transcript links
a11y adjustment to new video and transcript links styles
Segregate the mongo db config from the modulestore config
as a first step to separating db connection from modeling
and to support location mapper and contentstore using same db config as modulestore
Clarify USE_I18N settings

@jzoldak showed me that setting `USE_I18N = DEBUG` didn't actually accomplish
what I had hoped it would -- changing DEBUG didn't also change USE_I18N.
This pull request accomplishes what I was trying to accomplish, without being
quite so clever about it.
Suppress request logging in the LTI test server.
Write to stdout to keep messages, but not pollute tests.
Remove the now-unused import.
add some middleware to determine whether draft modulestore or non-draft modulestore should be used

change to use regex to do the domain mappings. Also add config to AWS to be able to set from configuration file.

handle cases where HTTP_HOST is none, like in unit tests

add linefeed at end

fix up regex matches

switch to use thread local storage to hold the request itself

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convert over to use open source 3rd party library

convert over to use django-cum

add unit test

remove comment

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add comment to config setting

fix comment

use better regex for localdev

no need to break

no need to wrap an imported function, it's visible to any file that is importing us

add comment

add unit test

clean up test

use a separate env file to set the preview hostname
Increase requirejs load timeout to 60 seconds
ux cleanup of video and transcript download buttons
updating video download links to a list - review feedback
Delete unused static-pages.html.
Fix intermittently failing video js tests
Certificates: Add regeneration command

* Adds regenerate_user command, which lets you run certificates for one
  particular user in one particular class, regardless of whether they
  have a pre-existing certificate.
Updated comment
grading.js depends on jquery.ui
Merge pull request #1240 from edx/dhm/config_separation

Segregate the mongo db config from the modulestore config
Merge pull request #1279 from edx/ned/remove-cache-warning-from-tests

Remove the now-unused import.
Merge pull request #1269 from edx/db/clarify-debug

Clarify USE_I18N settings
Defined baseUrl in the legacy instructor dashboard template, fixing a bug where the HTML editor would fail to load