Move incoming_list logic into conversation view_definition.
Remove old_start, end_conversation and tag acquisition from conversation wrapper. Also fix all the things that relied on those.
pep8/pyflakes cleanup.
Merge branch 'develop' into feature/issue-639-old-conversation-cleanup-pt-1

Conflicts:
	go/contacts/views.py
GroupsResource for sandbox
Hook up new incoming_list conversation view to conversation dashboard.
Merge branch 'develop' into feature/issue-644-groups-resource
Merge branch 'develop' into feature/issue-633-make-incoming-list-part-of-conversation-and-router-view-defn
Fix a bunch of tests.
incoming_list -> message_list.
Unskip some more tests.
Merge branch 'develop' into feature/issue-633-make-incoming-list-part-of-conversation-and-router-view-defn
Merge branch 'develop' into feature/issue-639-old-conversation-cleanup-pt-1
Merge branch 'feature/issue-633-make-incoming-list-part-of-conversation-and-router-view-defn' into develop
Merge branch 'develop' into feature/issue-639-old-conversation-cleanup-pt-1

Conflicts:
	go/conversation/views.py
Use helpers instead of status constants.
add get_by_name() get_or_create_by_name(), remove get_by_key()
docstrings
Merge branch 'feature/issue-644-groups-resource' into develop
Merge branch 'develop' of github.com:praekelt/vumi-go into develop