C14N selections

[Rod Widdowson]

Most for Scott,
Am I correct in assuming that the idea is that things like SP based
selection will go into the Activation Condition, but format mismatch should
be handled by the  @event {@link AuthnEventIds#RESELECT_FLOW}

Both could be done in either place and obviously testing up front can be
cheaper, but in some way it seems that the C14 Stage understands the NameID
and should do that selection, but needs know nothing about SPs and so it can
be left for something else

Rod