Internationaliztion: UTF-8 for file names

["Joseph Galbraith" <galb-list%vandyke.com@localhost>]

As currently specified, I do not believe SFTP meets
the requirements of "IETF Policy on Character Sets
and Languages" [RFC2277].

Last time this issue was raised, it stalled out on
issues of normalization.

I've now read the NFS specification on the matter
[RFC3010, section 11.]  NFS elected to not deal
with the normalization.  I would say that this
would be a great deal better than what we have
now (which is non-interoperability for filenames
that are not 7-bit US-ASCII).  I would also
say that if it was good enough for NFS, it is
probably good enough for SFTP.

I would propose that we reference the 
RFC3010, section 11 and specify UTF-8
for filenames.

On particularly compelling argument 
(at least to me) specified in RFC3010
is that a universal character set is
required because various path components
may be specified in different character-sets.

So, for example, trying to negotiate the
char-set in use during protocol startup or
even on a per path basis, is insufficient.

- Joseph