Use ssh's "-W" option instead of "/bin/nc"

[grigutis]

Consider this an enhancement request…

In reading the man page for ssh-copy-id, I found this tidbit:

N.B. the modern approach is to use the -W option, rather than nc

I don't know if this has any other benefits (or drawbacks), but it does eliminate a dependency on nc.

To implement this, the connect.applescript would need to replace all instances of /bin/nc %h %p with -W %h:%p.
admin-wrapper.sh also references /bin/nc, but I'm less sure how best to change that. Maybe that testCmd could be eliminated altogether.

Just something to think about.