Remove SNUI and phtml from testing

[Matthew Palmer <mpalmer@debian.org>]

Both SNUI and phtml have, to the best of my knowledge, no users.  Popcon
reports no installations (although, with 3 machines reporting, I'm not sure
that's so indicative).  However, I've never received any communication about
any of them.

I am considering making SNUI more widely known, but I'm not keen on it going
into a stable release without anyone ever having really tested it.

On Colin's advice, I've filed serious bugs on snui and phtml to prevent
testing migration, and am hereby requesting the following packages' removal
from testing:

snui-common
snui-server
snui-client
snui (source)
phtml (source and binary)

Thanks,
- Matt