Implement originalhost/host separation and Match support

Signed-off-by: Rui Li <ruili3422@gmail.com>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>

include/libssh/session.h

@@ -286,6 +286,9 @@ struct ssh_session_struct {
         int control_master;
         char *control_path;
         int address_family;
+        char *originalhost;        /* user-supplied host for config matching */
+        bool config_hostname_only; /* config hostname path: update host only,
+                                      not originalhost */
     } opts;
 
     /* server options */