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.
