Allow utf-8 usernames in scp

[Keisial]

Hello,

scp(1) doesn't allow copying files to a remote host with a username 
containing utf-8 characters. It just returns "invalid user name".
While traditionally usernames were restricted to printable us-ascii, 
nowadays there's little problem in allowing them. In fact, it is allowed 
by ssh, and even scp when copying _from_ such username.
The limitation seems to lie on the if (c & 0200) goto bad; check on 
okname() at scp.c, which automatically rejects usernames with the high 
bit set.

Can you please remove such limitation?
Thanks,