Settings for ENABLE_STUDENT_NOTES and ENABLE_TEXTBOOK in CMS.
Do not display empty collection tabs.
Updated Changelog.

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-1183

STUD-850

Conflicts:
	cms/djangoapps/contentstore/features/advanced-settings.feature
	cms/djangoapps/contentstore/features/checklists.feature
	cms/djangoapps/contentstore/features/component.feature
	cms/djangoapps/contentstore/features/course-overview.feature
	cms/djangoapps/contentstore/features/course-settings.feature
	cms/djangoapps/contentstore/features/course-team.feature
	cms/djangoapps/contentstore/features/course-updates.feature
	cms/djangoapps/contentstore/features/courses.feature
	cms/djangoapps/contentstore/features/discussion-editor.feature
	cms/djangoapps/contentstore/features/grading.feature
	cms/djangoapps/contentstore/features/html-editor.feature
	cms/djangoapps/contentstore/features/problem-editor.feature
	cms/djangoapps/contentstore/features/section.feature
	cms/djangoapps/contentstore/features/signup.feature
	cms/djangoapps/contentstore/features/static-pages.feature
	cms/djangoapps/contentstore/features/subsection.feature
	cms/djangoapps/contentstore/features/textbooks.feature
	cms/djangoapps/contentstore/features/upload.feature
	cms/djangoapps/contentstore/features/video-editor.feature
	cms/djangoapps/contentstore/features/video.feature
	lms/djangoapps/courseware/features/certificates.feature
	lms/djangoapps/courseware/features/help.feature
	lms/djangoapps/courseware/features/high-level-tabs.feature
	lms/djangoapps/courseware/features/homepage.feature
	lms/djangoapps/courseware/features/login.feature
	lms/djangoapps/courseware/features/lti.feature
	lms/djangoapps/courseware/features/navigation.feature
	lms/djangoapps/courseware/features/problems.feature
	lms/djangoapps/courseware/features/registration.feature
	lms/djangoapps/courseware/features/signup.feature
	lms/djangoapps/courseware/features/video.feature
	lms/djangoapps/courseware/features/word_cloud.feature

We used to use a regular JS `confirm`; this makes the UI consistent
with the rest of Studio.

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

% to format
css_find().click() to its actual function
A few name changes as well as step changes
Removal of drag testing
A refactoring of login and create user.  Login will no longer create the specified user

Also added in drag and drop helper.  Please be careful using this method as it is truly a hack to obtain the visual effects.  As of this commit, selenium does not support drag and drop for jQuery sortable items