Added optional filters property to deepFetch.
Note that additional indexes are required whenever this is used.
Reviewed by: Lennard de Rijk
"""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