add scp path to _PATH_STDPATH

[mouring at etoh.eviladmin.org]

On Fri, 2 Mar 2001, Damien Miller wrote:
[..]
> 
> I agree - if people are specifying a PATH themselves, then it is not too
> much to ask that it be correct.
> 

Which really brings up another can of worms..

Since not everyone installs OpenSSH in the same place.. sftping between
machines is a nightmare.

$ sftp -1 etoh
Connecting to etoh...
mouring at etoh's password:
bash: /usr/libexec/sftp-server: No such file or directory
Couldn't read packet: Undefined error: 0


If we are going to solve scp.  We should resolve where sftp-server is to
make sftp using protocol 1 easier.  

- Ben