Last step of refactoring before adding support for > 1000 entities.
Make helper functions. One extracts list parameters.
One creates links more simply. This is cleaning up the large
function body so I can move stuff around more radically.
Patch by: Dan Bentley
"""Multi-consumer multi-producer dispatching mechanism
Originally based on pydispatch (BSD) http://pypi.python.org/pypi/PyDispatcher/2.0.1
See license.txt for original license.
Heavily modified for Django's purposes.
"""
from django.dispatch.dispatcher import Signal