Task groups properly mapped to objects and tasks;
autocomplete refactored to allow subclassing, made subclass that filters on an object's mapping;
task group widget updated with semi-functioning objects mapper with lookup autocomplete for workflow objects (task not yet implemented)
Task group's task list is live, with add/remove functionality, and drag handles for reordering.  Lock order checkbox is not yet implemented.
Locking/unlocking of task order implemented
Enabling confirm delete from TaskGroup tree view
Fixed up task listing and re-tasking directly in list, enabled task group deletion, disabled handles and trash icon when task order locked.
Refactored component inserted event to use can.Control-y syntax
Merge remote-tracking branch 'origin/feature/task-groups' into feature/initial-workflow-cycles

Conflicts:
	src/ggrc_workflows/__init__.py
	src/ggrc_workflows/assets/assets.yaml
	src/ggrc_workflows/assets/javascripts/apps/workflows.js
	src/ggrc_workflows/models/task_group.py
Fix migration ordering