Added check_field_is_empty decorator to cleaning.py. This makes sure the cleaning checks are skipped when a field is empty. Note that Djanog will raise it's own ValidationError when a required field is empty before attempting to clean it. Patch by: Lennard de Rijk Reviewed by: to-be-reviewed.

"""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