2017-10-17:  Class names finalized:
             Core/base class  -> Ssh
             Session class    -> SshSession
             SFtp class       -> SFtp
             Channel class    -> SshChannel
             Scp class        -> Scp
             Exec class       -> SshExec
             Knownhosts class -> SshHosts
             SshAgents        -> (will be added as such)

             CreateSFtp(), CreateExec(), CreateScp(), CreateChannel() methods added to SshSession
             class. 
             Logging further refined.
             Error management further refined.

void GetFileInfoViaExec(SshSession& session)
{
	DLOG("---- Getting directory listing of " << file << " using SshExec (blocking):");
	auto exec = session.CreateExec();
	DDUMP(exec(String(cmd) + file, Cout(), Cerr()));
	
}

CONSOLE_APP_MAIN
{
    StdLogSetup(LOG_FILE | LOG_COUT | LOG_TIMESTAMP);

//  Ssh::Trace();
    SshSession session;
    session.WhenProxy = [=](TcpSocket& sock) {
        NetProxy proxy(sock, proxy_host, proxy_port);
        return proxy.Timeout(10000)
                    .Socks5()
                    .Auth(proxy_username, proxy_password)
                    .Connect(ssh_host, ssh_port);
    };
    if(session.Connect(ssh_host, ssh_port, username, password)) {
        auto exec = session.CreateExec();
        DDUMP(exec("ls -l /readme.txt", Cout(), Cerr());
    }
    else Cerr() << session.GetErrorDesc() << "\n";
}