Merge branch 'master' of github.com:edx/edx-platform into bugfix/ichuang/make-edit-link-use-static-asset-path

Conflicts:
	common/djangoapps/xmodule_modifiers.py
lms namespace removed
module -> block in common/djangoapps/xmodule_modifiers.py
Merge branch 'master' of github.com:edx/edx-platform into bugfix/ichuang/make-edit-link-use-static-asset-path
Add feature to do auto signup with external auth
This adds a feature flag: AUTH_USE_MIT_CERTIFICATES_IMMEDIATE_SIGNUP
that does an automatic signup of users if they are using external authentcation.
Fixed PEP8 and indentation issues
Added tests for signup skipping
Corrected CMS tests so that one is passing, added external_auth to cms apps
Several pylint fixes and bad super call
Removing external_auth addition to cms, and skipping test
Refactor keypress activation for forum buttons

This removes the use of the space key to activate buttons, which is not
expected behavior.
Improve accessibility of inline discussions

The show/hide toggle now properly acts like a button, and focus is now
trapped on the loading element for both the show/hide action and loading
of a new page.
Enable un-authenticated handler urls

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>
Rename the LTIModuleDescriptor to LTIDescriptor to follow convention
Add a per-course anonymous student id

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
Make FieldDataCache use the user from scope_ids, rather than its pre-configured user

Co-author: Ned Batchelder <ned@edx.org>
Add grading functionality to LTI xmodule

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]
Change video transcripts to use locators instead of locations.

Part of STUD-870
Merge pull request #1791 from cpennington/rebased-lti-graded

BLD-384: Add grading to LTI module
Resolve conflicts merging master to rc/2013-11-21
Merge pull request #1802 from edx/ned/merge-master-to-rc-2013-11-21-again

Merged master to rc/2013-11-21, so we can merge it back to master.