Correct three typos in video documentation

Allow user with BetaTester role correctly use LTI. BLD-641.

Use subprocess.STDOUT, rather than sys.STDOUT to rebind stderr

i18n xmodule/course_module.py

Persist speed preferences between videos.

Added a .po segmenting tool

Use the configuration more, and we don't need to delete files we're
about to create.

Messages can be segmented into different .po files based on the location
of their occurrences.  This is so Studio strings can go into different
.po files so we can direct Transifex workers to the LMS strings we
really need done.

Bok choy tests output XUnit reports

Markhoeber/documentation/release notes 1 23 14

Remove comment for how to install PIL

LMS-1747

Remove CONTRIBUTING.md

resubscribe feature for notifier

Merge "video sources" and "download video" into the same field

Github includes a "Please review the guidelines for contributing
to this repository" link when creating a pull request, and it links
to the Markdown version of this file, which is annoying. Removing
the file should redirecto the link to the reStructuredText version
of this file.

We use Pillow now, which can be installed via PyPI

Enable microsite tests

Make video debug messages consistent.

Move microsite test assets to common/test

Rename helper method to not have test in the name
Rename test css file

Add tests of compiled translated strings, so that we can check them into the repo safely.

Make problem types pluggable.

Fix video progress slider method.

Fix video code duplication.

rangeParams returned from getRangeParams() function is already
an object that contains the left and width properties. It can
be passed directly to the jQuery css() function.

In each Video JavaScript module, methods are either private,
or public. When a method is public, it is made available via
the state variable. It seems that a while ago one method
was made public, but throughout the code it is used as a private
method. This has been corrected.

In the JavaScript console all messages from the Video
player should begin with "[Video info]: ". This way it
is easier to see which console.log() messages are from
the Video player, and which console.log() messages are
temporary, and should be removed before a merge/commit.

This patch adds the ability for arbitrary packages to register
themselves with xmodule.x_module.ResourceTemplates as being providers of
boiler plate templates used for defining the types of problems
instructors can add to a course.  This allows third party add-ons to
define new problem types that can then be available to instructors to
use.

This patch is the result of discussion with Ned Batchelder on the right
way to approach this problem.  The solution provided here is,
admittedly, a little bit of a hack.  But the focus was on making a least
invasive fix to make something work, in anticipation that when problems
get moved into the newere XBlock architecture something a little nicer
will be in place.

Create mapping for previously unmapped locations in order to get