Add an option to disable client window resizes

This goes great with tmux when you are sharing your terminal for
presentations and you don't want to give viewers the ability to resize
your terminal

main.go

@@ -37,6 +37,8 @@ func main() {
 		flag{"once", "", "Accept only one client and exit on disconnection"},
 		flag{"permit-arguments", "", "Permit clients to send command line arguments in URL (e.g. http://example.com:8080/?arg=AAA&arg=BBB)"},
 		flag{"close-signal", "", "Signal sent to the command process when gotty close it (default: SIGHUP)"},
+		flag{"width", "", "Static width of the screen, 0(default) means dynamically resize"},
+		flag{"height", "", "Static height of the screen, 0(default) means dynamically resize"},
 	}
 
 	mappingHint := map[string]string{