Adding missing forum permissions seeding routine to xml_import
Currently if a course is only imported from the command line the
forum permissions are not seeded, this adds that functionality
Switched to doing seeding outside of xmodule library
Switched to using course_items
Switching to simpler test class
Merge pull request #2196 from carsongee/cg/forum_roles_on_import_command

Adding missing forum permissions seeding routine to xml_import