[PATCH] Peer selection

Now that we are generating the set of possible peers before attempting
to connect. The retry_on_error directive is no longer repeatedly
cycling through the peer selecting process failing on one peer until
that peer works.

The maybe-direct case seems to have been depending on this behaviour to
locate alternative peers before going DIRECT. The attached patch seeks
to make the maybe-direct case produce a list of all available parents
with the specific algorithm choice first.

Amos

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