Make timeout time configurable from the control port

This change is backwards compatible. If a "timeout" value is not submitted
to the control port then the default value of 30s will be used.

vncap/control.py

@@ -32,6 +32,7 @@ def lineReceived(self, line):
             ws = d.get("ws", False)
             tls = d.get("tls", False)
             client_opts = d.get("client", {})
+            timeout_secs = d.get("timeout", 30)
 
             # Allocate the source port.
             sport = self.factory.allocate_port(sport)
@@ -52,7 +53,7 @@ def timeout():
                 log.msg("Timed out connection on port %d" % sport)
                 listening.stopListening()
                 self.factory.free_port(sport)
-            reactor.callLater(30, timeout)
+            reactor.callLater(timeout_secs, timeout)
 
             log.msg("New forwarder (%d->%s:%d)" % (sport, host, dport))
             self.sendLine("%d" % sport)