Fix repeated doc builds
Make builds quiet by default
Add verbose option
Fix import mocks.

    Prevents sphinx from bailing on builds that involve unavailable imports.
was getting unicode errors when exporting CB22x
export_to_xml() really should be definition_to_xml() since we'll rely on the base method that is in xml_module.py to preserve the correct export filesystem hierarchy.
remove commented out line
update tests to call definition_to_xml rather than export_to_xml, which presumes writing to a filesystem, plus it adds a url_name to the attribute set. Also, on __init__ reset the 'category' attribute, on some code paths this can get lost. Not sure why, but this gets all the tests to pass.
Make our deserializing consistent with serializing.

Also fixes problems with double-quoted strings (historical artifact).

STUD-640

Conflicts:

	common/lib/xmodule/xmodule/video_module.py
Add test for invalid YouTube IDs strings
have XModuleDescriptor properly ensure category is set
use same getattr pattern in the XModule constructor that exists in the XModuleDescriptor
Change registration button based on number of modes.
Add new column to CourseMode table for currencies
Add in tests for the marketing site button.
small change in aggregating peer eval grades (rounds up)
Enable the django_nose app by default

The django_nose it is very useful, even outside the test
environment. For example, it lets you to easily run test from
manage.py without additional changes to the test packages.
initial commit for a mixed module store which can interoperate with both XML and Mongo module stores
add a set_modulestore_configuration to the modulestore interface. This can be used to pass in settings run the Django tier
WIP: added a get_modulestore_type. Added some unit tests. changed over the isinstance() with respect to modulestores to use this get_modulestore_type()