Identify ssh client version with more info and sshd server shows it by an env var

MS Win32 port & build date added in text part of version id ssh client
send to the remote sshd. sshd also shows this string via environment
variable  "SSH_CLIENT_ID" . All these are allowed and encouraged by the
SSH RFC and improves usability and assists users to know what ssh
versions and vendor build they are running.

ssh_api.c

@@ -382,7 +382,11 @@ _ssh_send_banner(struct ssh *ssh, char **bannerp)
 	char buf[256];
 	int r;
 
+	#ifndef WIN32_FIXME
 	snprintf(buf, sizeof buf, "SSH-2.0-%.100s\r\n", SSH_VERSION);
+	#else
+	snprintf(buf, sizeof buf, "SSH-2.0-%.100sp1 Microsoft Win32 port %s\r\n", SSH_VERSION, __DATE__ );
+	#endif
 	if ((r = sshbuf_put(ssh_packet_get_output(ssh), buf, strlen(buf))) != 0)
 		return r;
 	chop(buf);

sshconnect.c

@@ -677,8 +677,13 @@ send_client_banner(int connection_out, int minor1)
 {
 	/* Send our own protocol version identification. */
 	if (compat20) {
+		#ifndef WIN32_FIXME
 		xasprintf(&client_version_string, "SSH-%d.%d-%.100s\r\n",
 		    PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2, SSH_VERSION);
+		#else
+		xasprintf(&client_version_string, "SSH-%d.%d-%.100sp1 Microsoft Win32 port %s\r\n",
+		    PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2, SSH_VERSION, __DATE__ );
+		#endif
 	} else {
 		xasprintf(&client_version_string, "SSH-%d.%d-%.100s\n",
 		    PROTOCOL_MAJOR_1, minor1, SSH_VERSION);

sshd.c

@@ -795,6 +795,10 @@ sshd_exchange_identification(int sock_in, int sock_out)
 	debug("Client protocol version %d.%d; client software version %.100s",
 	    remote_major, remote_minor, remote_version);
 
+	#ifdef WIN32_FIXME
+	SetEnvironmentVariable("SSH_CLIENT_ID", remote_version);
+	#endif
+	
 	active_state->compat = compat_datafellows(remote_version);
 
 	if ((datafellows & SSH_BUG_PROBE) != 0) {