[ca-tf] Further CA work

[Nigel Titley <nigel.titley@localhost]

Bearing in mind Russ's question in the NCC services group. When are we
likely to be taking steps beyond the first PKI portal? As he points out,
this is only the first step and is not really very useful on its own.

Assuming this goes forward, the CA-TF needs to start chasing things like
the up-down protocol. Do we have plans for this?

Nigel