All YouTube urls are defined on backend side.

Changed "Status Page" -> "Page".

UX:
    support for displaying built-in tabs
    restored drag and drop on Studio Pages
    additional styling for fixed state on Studio Pages
    add a new page action added to bottom of Studio Pages

Dev
    changes for viewing tabs in studio,
    refactored the tab code,
    decoupled the code from django layer.
    is_hideable flag on tabs
    get_discussion method is needed to continue to support
external_discussion links for now since used by 6.00x course.
    override the __eq__ operator to support comparing with
dict-type tabs.

Test
    moved test code to common,
    added acceptance test for built-in pages
    added additional unit tests for tabs.
    changed test_split_modulestore test to support serializing objects
that are fields in a Course.

Env:
    updated environment configuration settings so they are
    consistent for both cms and lms.

STUD-600

with code to translate between addressing schemes based on app
and persistence layer addressing scheme specification.

STUD-1206

[LMS-226]
[LMS-2013]

Refactored stub services for style and DRY

Added unit tests for stub implementations

Updated acceptance tests that depend on stubs.

Updated Studio acceptance tests to use YouTube stub server; fixed failing tests in devstack.

This reverts commit a517dc20.

This reverts commit ec01253e, reversing
changes made to ae8c9710.

@jzoldak showed me that setting `USE_I18N = DEBUG` didn't actually accomplish
what I had hoped it would -- changing DEBUG didn't also change USE_I18N.
This pull request accomplishes what I was trying to accomplish, without being
quite so clever about it.

as a first step to separating db connection from modeling
and to support location mapper and contentstore using same db config as modulestore

We want USE_I18N to be on in development, but off in production. Tying
this setting to the DEBUG setting accomplishes that neatly.

Add AUTOMATIC_VERIFY_STUDENT_IDENTITY_FOR_TESTING flag so that acceptance tests can run through certificate identity verification flow.

use to instantiate loc_mapper
test loc_mapper injection into split modulestore

CMS tests should now run on IE

CMS tests will now run on Safari

Rebased wrong

Forgot to update the test_acceptance.sh

Changed way of string splitting

Forgot an import