(cherry picked from commit a7c0a2a)

Also contains:

* mattdrayer/rebase-20140722b: cherry-pick 0325694
* mattdrayer/rebase-20140722: cherry-pick e8b1217
* Sessions API Documentation
* mattdrayer/rebase-20140722: cherry-pick ofao48d
* mattdrayer/rebase-20140722: cherry-pick b0c343c
* mattdrayer/rebase-20140722: cherry-pick d56e973
* mattdrayer/status-500-fix: Small API bug
* added content_id to workgroup review submissions
* mattdrayer/api-user-preferences-delete: Added new Detail view, GET/DELETE operations
* mattdrayer/rebase-20140722: cherry-pick 0624385
* handle exception if user never accessed any course module
* mattdrayer/rebase-20140722: cherry-pick caada51
* cdodge/add-progress-publish-api-endpoint: expose a new xblock runtime publish special cased event type 'progress' which adds an entry into the CourseCompletions table
* add default setting for feature flag in common.py
* mattdrayer/rebase-20140722: cherry-pick 7a1e12c
* mattdrayer/rebase-20140722: Functional stabilization

Conflicts:
	cms/djangoapps/contentstore/views/helpers.py
	common/static/coffee/src/discussion/content.coffee
	common/static/coffee/src/discussion/discussion_filter.coffee
	common/static/coffee/src/discussion/discussion_module_view.coffee
	common/static/coffee/src/discussion/discussion_router.coffee
	common/static/coffee/src/discussion/views/discussion_content_view.coffee
	common/static/coffee/src/discussion/views/discussion_thread_profile_view.coffee
	common/static/coffee/src/discussion/views/discussion_thread_show_view.coffee
	common/static/coffee/src/discussion/views/discussion_thread_view.coffee
	common/static/coffee/src/discussion/views/new_post_view.coffee
	common/static/coffee/src/discussion/views/response_comment_show_view.coffee
	common/static/coffee/src/discussion/views/thread_response_show_view.coffee
	common/static/coffee/src/discussion/views/thread_response_view.coffee
	lms/djangoapps/django_comment_client/forum/views.py
	lms/static/sass/discussion/_discussion.scss
	lms/templates/discussion/_discussion_module.html
	lms/templates/discussion/_filter_dropdown.html
	lms/templates/discussion/_js_head_dependencies.html
	lms/templates/discussion/_thread_list_template.html
	lms/templates/discussion/_underscore_templates.html
	lms/templates/discussion/index.html
	lms/templates/discussion/mustache/_inline_discussion.mustache
	lms/templates/discussion/mustache/_pagination.mustache
	lms/templates/discussion/mustache/_profile_thread.mustache

added avatar url field

muhhshoaib/security-change-user-password-requirements-685: handled password complexity scenarios messages according to Chris Suggestions

muhhshoaib/security-change-user-password-requirements-685: changed the chracteres storage from sets to lists

asadiqbal08/api_support_title_field_userprofile: [MCKIN-1241] Added support for title field to edX user profile

Included commits:
* xblock-external-ui: Include CSRF token in the API answer
* xblock-external-ui: Adds support for CORS headers (cross-domain request)
* xblock-external-ui: Include full path when building local_url
* xblock-external-ui: Fix TestHandleXBlockCallback & bok_choy, add tests
* xblock-external-ui: Only return `instance` in `_invoke_xblock_handler()`
* xblock-external-ui: Group resources by hash tag to avoid duplicate loads
* xblock-external-ui: Alternate referer check for CORS requests
* session-cookie-httponly: Allow to disable httponly on session cookies
* remove errant log message
* xblock-no-anonymous: Fail early if the XBlock view is called anonymously

TNL-2413

This migration instantiates the modulestore which is now dependent
the xblock_django database config settings.  So the initial migration
for that has to run before this migration.

Includes the changes from 897fddba.
Those changes were introduced while resolving a merge
conflict from release back into master.

TNL-2305

* Remove m2m relation between credit course and credit providers.
* Separate eligibility and provider APIs into different modules.
* Add API call for retrieving a user's eligibilities.
* Cache credit course list.
* Style the dashboard purchase button.
* Display a link for the credit provider on the dashboard.
* Add analytics events for clicks on the purchase button.
* Expose more credit models to Django admin and add search functionality.

ECOM-1734

Check if the request's user is authenticated before attempting to
get their user preferences. Otherwise, log warnings appear indicating
the UserNotFound error was caught.

Adds standardized audit logging for checkout and enrollment change requests. XCOM-427.

Adds a temporary user_preference key, DARK_LANGUAGE_KEY, to hold the user's dark lang preference.
This preference key is deleted when ?clear-lang is placed in query params.

LOC-87

Only return languages we've actually released LOC-85
Perform fuzzy matching to greedily serve the best released language LOC-72