The echoserver's -A mode runs an accepted scp command through
wolfSSH_SCP_accept(). Reaching that call's want retry path takes a
non-blocking server, which -N supplies.
- copy to and from an app-driven server in scp.test
- check the entry point's null-session argument
The scripts now read the build options from the probe instead of grepping
usage text, config.log and daemon logs. Drops the usage lines only tests read.
Simulate netowrk latency using netem and use it to test the non-blocking
mode of SFTP. This helps find issues which would affect running an SFTP
server on a microcontroller. It helped find the bug fixed in #876.
1. Update scp.test to delete the empty test file.
2. In wolfSSHd, when coverting an IP address to a printable
representation, the destination needs to be able to handle IPv6
addresses potentially.