start of EditConversationGroupsView
list and link groups
slightly more consistent UI
removing contact upload from group selection view
fixing #578 turned out to be easy
pep8 fixes
Merge branch 'develop-frontend' into feature/issue-572-edit-contacts-view

Conflicts:
	go/conversation/view_definition.py
test for conversation group management
splitting tests into two
fix title and remove breadcrumbs js (thanks @Hodgestar)