Avoid recomputing course module information for every thread, which
should dramatically improve the performance of high-percentile latency
queries.

JIRA: FOR-250

CommentClientError now has sane subclasses that are meaningfully
distinct, and each subclass is handled appropriately. Errors raised by
the requests library are no longer handled by turning them into
CommentClientErrors, since there is no meaningful handling we can do,
and this way we will get more visibility into why errors are occurring.
Also, HTTP status codes from the comments service indicating client
error are correctly passed through to the client.

Use the leanModal stuff to show the cheatsheet dialog in the wiki.

LMS-1303

Move RESTful URLs into our "done" section.

To help fix recent bugs re orphaned discussions and
to prototype a more restful json oriented api.

STUD-590

Fixing falling test. Added fix for RequireJS & XModule loader video race condition.
Removed unnecessary comments from SCSS and JS files.
Added entry to Change Log.

Made it so that the link and the text are on the same level, and in the
center of the block.

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

.

.

convert over to use open source 3rd party library

convert over to use django-cum

add unit test

remove comment

.

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

Also includes RequireJS changes.

Fixes bugs:
STUD-755, STUD-152, STUD-700, STUD-699

Add the text_customization dict in advanced settings, which contains
customizations checked in specific spots. Here it is used to enable
the customization of the "Check" and "Final Check" button titles
under the keys custom_check and custom_final_check.

Just works on the tabs list in mongo, nothing
deeper than that.
Added implementation functions in tabs.py,
providing a first step for some future
GUI editor.