Part of STUD-1030

Co-author: Alexander Kryklia <kryklia@edx.org>
Co-author: Ned Batchelder <ned@edx.org>
Co-author: Oleg Marchev <oleg@edx.org>
Co-author: Valera Rozuvan <valera@edx.org>
Co-author: polesye
[BLD-384]

This does not yet replace the existing per-student anonymous id, but
is intended to do so in the future.

Co-author: Alexander Kryklia <kryklia@edx.org>
Co-author: Ned Batchelder <ned@edx.org>
Co-author: Oleg Marchev <oleg@edx.org>
Co-author: Valera Rozuvan <valera@edx.org>
Co-author: polesye

Updates to depend on the latest version of XBlock, which includes
support for service-to-service (thirdparty) handler urls, which aren't
authenticated with a user (unlike handler requests coming from the
xblock client-side javascript).

Co-author: Ned Batchelder <ned@edx.org>

Adds xblock handler_url support to the LMS, and makes handle_ajax use
that code.

[LMS-230] [LMS-229]

[LMS-57]

By transparently proxying between the XModuleDescriptor and the XModule,
and between their runtimes, we can make them act as a single class, so
that we can swap in an actual XBlock instead.

Modified navigation tests to use MixedModulestore
Updated factories to find editable modulestore

Updated test_submitting_problems

Updated test_tabs.py

Updated test_view_authentication

Updated test_views

Updated courseware/tests/tests.py

Updated test_masquerade

Updated test_module_render

Pylint fixes

Updated video and word cloud tests

Updated course wiki tests

Updated license and open_ended tests.
One open_ended test still failing due to Mako initialization issues

Updated staticbook

Updated django_comment_client tests

Updated instructor tests

Updated instructor task tests

Updated external_auth tests

Updated course_groups

fix (again) static_replace to work with static_asset_path

This makes the LMS use an XBlock's student_view, rather than an
XModule's get_html to render for display. However, it does not yet use
wrap_child to handle instructor debug information or url rewriting.

[LMS-219]

Embedded discussion component defaults to "Discussion"
Blank HTML page defaults to "Text"
Video component defaults to "Video"

These default names show up in tooltips.

change from_xml class method on video class to make sure we honor the fact that the xml string could actually be a pointer to another file on disk which actually contains the attributes

Update existing tests and provide new ones to test new paradigm.

Moved xml_store_config, mongo_store_config, and draft_mongo_store_config to xmodule/modulestore/tests/django_util.py
Removed some repeated instances of xml_store_config.
Reverted some changes to mongo_store_config so each modulestore gets it's own uuid.

Add unit tests for creating VideoDescriptor from old XML. Brings test coverage for video_module.py to 91%.

Update XML in old video tests. This change tags like <video youtube="1.0:abcdefg"> to <video youtube_id_1_0="abcdefg".

add fixes for 500 bugs (lighthouse 287 and 293) by requiring login for accessing licenses and inline discussions.  Add unit tests for licenses, and rearrange tests based off of (the former) PageLoad.  Also cleanups for pylint and pep8.

Return a 403 when an anonymous user attempts to hit modx_dispatch. Fixes https://www.pivotaltracker.com/story/show/46916015 and https://www.pivotaltracker.com/story/show/46916029

of the tests fail.  Deleted some tests.