Clean up of modulestore references (primarly LMS).

STUD-1151
Enable XBlocks in bok_choy tests
Small tweak to early-translation fix docs
add push_to_lms to Studio; uses MITX_FEATURES['ENABLE_PUSH_TO_LMS']
Push To LMS updates
Added tests
Converted scripts to django commands
Removed advanced module requirement
Generalized to platform
Switched to subprocess for shell commands
Beefed up resiliency and error checking.
Refactored since #1910 removed get_location_and_verify_access
Added settings to aws for export directory and reworked test setup and teardown
Several review based fixes
Added line to Changelog
Changed URL handler to be accepting and moved git bare repo inside of test_root/data
Added exception logging to help trace issues
Added output in exception logging
Made the branch to commit to explicit instead of implicit
Skipping git identity test on condition of global configuration set
Update translator documentation
Major refactor and rename of feature
All forward facing wording changed to Export to Git
Export to git functions removed from management command and put in common file
Additional error checking and documentation improvements
Nitpicks and other minor fixes
Fix LMS-2249 (https://github.com/edx/edx-platform/issues/2516)
Add trailing commas to multiline lists, to prevent string concatenation bugs
Added labels to CAPA input types, with markdown syntax for adding them
in studio.
LMS-1895 and others
Merge pull request #2426 from edx/dcs/a11y-labels

Add labels to CAPA inputtypes.
LMS-1895
Add acceptance tests using the AcidBlock for LMS and Studio

[LMS-1645]
[LMS-2062]
[LMS-2063]
[LMS-2064]
Merge pull request #2555 from cpennington/xblock-acid-acceptance-tests

Add acceptance tests of the Acid block in both LMS and Studio
Merge pull request #2590 from edx/ned/small-tweak-to-early-translation-fix-docs

Small tweak to early-translation fix docs
Merge pull request #2597 from edx/release

Release
Merge pull request #2589 from edx/sarina/update-i18n-translator-docs

Update translator documentation
Check for forum data errors in LMS

Some messages generated by the comments service are not readily
translated because they come from third-party libraries. Thus, we plan
to try to avoid showing any comments service generated message to the
user. This check preempts the only end-user-visible CS-generated error
message that we are presently aware of.
Merge pull request #2585 from edx/gprice/lms-forum-error-check

Check for forum data errors in LMS
Removed default background image for home and courses pages
Merge pull request #2566 from edx/giulio/remove-edx-bg-image

Removed default background image for home and courses pages