Fix the deadline counter to start counting only after Task claim is accepted.
Deadline counter used to start when the task was claimed to be requested.
This commit fixes that.
"""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