Require newer version of Reg, just released.
Un-generic generic.consume, as we're not using it in a generic way.
See issue #244.
Un-generic generic.link, moving it into request. Part of #244.
Move get_response into publish and un-generic it. See issue #244.
This actually turns out to be nice: we can simplify the response
resolution.
Have the default behavior for generic.permits return False, which
lets us rid of a registration in core.py.