Pair requests the the same UUID are part of the same pairing session,
which allows us to detect attempts to brute force the shared secret,
as that will result in pair requests with the same UUID that are
not verified with the right secret.
The remote computer may not support mDNS. Instead, pass over the uname -a
hostname, and the IP address, and leave best hostname calculation to the
remote side.
Pair requests are sent on all network interfaces, and contain the best
available hostname to use to contact the host on that interface.
Added a pairing in progress page.
Revert "reduce some boilerplate using ghc extensions", because it caused
overlapping instances for Text.
Actually 3 forms in one, this handles the initial passphrase entry, and the
confirmation, and also varys wording if the same user or a different user
is confirming.
