Correct version number.
"Neatening" the filters region.

Until we come up with a nicer way of delegating regions computation this
allows us to reuse the same region logic for multiple instances of the
same region type.

Yuck.
Merge branch 'filters' into inhibition2

Include changes to use new filters mixin.

Conflicts:
	nengo_spinnaker/ensemble_vertex.py
	nengo_spinnaker/utils/filters.py