Make group_from_json_dict() load details for Group objects too
Add new Stem class for creating/manipulating stems
Add group/stem delete support
Use username as provided by the requests auth object.
Merge remote-tracking branch 'alexdutton/use-auth-username'

Conflicts:
	grouper_ws/api.py
Fix commented-out memberFilter parameter in get_memberships()
Add Subject API source selection to has_members() based on add_members()