Hide inactive person biographies from plugin

If a person biography is marked as inactive, it should not be available as an
option in its plugin. This corrects a mistake made where
PersonBiographyPluginForm (a ModelForm) was not assigned a model.
Mark package as not zip_safe

This package needs access to its templates to function. Thus, the
zip_safe flag has been set to False to tell setuptools to not
install the package's egg as a zip file.

See http://pythonhosted.org/distribute/setuptools.html#setting-the-zip-safe-flag
for further information.