--list-devices and binary version mismatch

[XavierChanth]

--list-devices in more recent versions of sshnpd will respond with the noports_core version instead of the sshnpd binary version (as it did previously). We should:

• Include the noports_core version in the usage info for all the binaries (since the noports_core version is what actually determines the capabilities of a particular device)
• Consider including the sshnpd binary version in the --list-devices output

@gkc can I leave this issue to you to look at more closely, since I know you've recently implemented similar capabilities for the SRDs?

[gkc]

Fixed by #659