examples: add public key authentication to ssh_server_fork
I noticed that there was no example showing server side public key encryption in the examples
so I added this one. I used authorizedkeys as a global to minimize the changes to the original
code as well as I was not sure the correct methodology of determining the .ssh directory location
for a user not using Linux. One code using the user parameter to determine the location to use
instead if desired.
Signed-off-by: Eric Bentley <email@example.com>
Reviewed-by: Andreas Schneider <firstname.lastname@example.org>