public delegate bool VerifyPeerCallback(VerifyPeerContext context)
Callback invoked with the expected targetHost and the peer's certificate.
If false is returned by this callback then it is treated as a
verification failure and the attempted connection will fail.
Invocation of the callback is blocking, so any
implementation should be light-weight.
Note that the callback can potentially be invoked multiple times,
concurrently from different threads (e.g. when multiple connections
are being created for the same credentials).
