Removed debug logging

Added verification of broadcast response message size
Added clearer handling of message types

I'm sure there's a better way to do debug logging, but I don't really feel like adding a dependency on another module just for that.

messages/SLLoginMessage.js

@@ -1,12 +1,18 @@
 const SLMessage = require('./SLMessage.js').SLMessage;
 
+const MSG_ID = 27;
+
 exports.SLLoginMessage = class SLLoginMessage extends SLMessage {
   constructor() {
-    super(0, 27);
+    super(0, MSG_ID);
     this.writeInt32LE(348); // schema
     this.writeInt32LE(0); // connection type
     this.writeSLString('node-screenlogic'); // version
     this.writeSLBuffer(Buffer.alloc(16)); // encoded password. empty/unused for local connections
     this.writeInt32LE(2); // procID
   }
+
+  static getResponseId() {
+    return MSG_ID + 1;
+  }
 }