add max-sockets CLI argument

bin/server

@@ -14,6 +14,10 @@ var argv = optimist
         default: '80',
         describe: 'listen on this port for outside requests'
     })
+    .options('max-sockets', {
+        default: 10,
+        describe: 'maximum number of tcp sockets each client is allowed to establish at one time (the tunnels)'
+    })
     .argv;
 
 if (argv.help) {
@@ -22,7 +26,7 @@ if (argv.help) {
 }
 
 var server = require('../server')({
-    max_tcp_sockets: 10,
+    max_tcp_sockets: argv['max-sockets'],
     secure: argv.secure
 });