Stylefixes in access.py and removal of self.deny calls
The result of self.deny() is not very helpfull to the user, as such
we should not use it if we can provide a more sensible message.
Also made the document access checks use getForKeyFieldsOr404 to
prevent an error page when the specified document doesn't exist.
Patch by: Sverre Rabbelier
"""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