Computed ID Data Connector

[Rod Widdowson]

Let me wind back and apologise.

The sha is computed on the:
 - inboundMessageIssuer (i.e. theSP)
 - the input attribute
 and then salted.

The IdP does entityID does *not* enter into the calculation.  I was getting
my issuers and my responders and my relying parties confused.  My apologies

Note that the CryptoTransient and Transient *attributes* (which are sort of
kinda related except when they are not) *do* care about the IdP entityID.

Rod