Added _getSurveyRecordFor method to Survey View.
This method is used by the Take view to get the right SurveyRecord for the current request. Subclassed Views that want to fetch their records in another way can override this method.
"""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