compatible with engine.io v0.7.3

src/main/java/com/github/nkzawa/engineio/client/Socket.java

@@ -601,6 +601,7 @@ public abstract class Socket extends Emitter {
                 public void run() {
                     self.writeBuffer.clear();
                     self.callbackBuffer.clear();
+                    self.prevBufferLen = 0;
                 }
             });
 

src/main/java/com/github/nkzawa/engineio/client/transports/WebSocket.java

@@ -135,7 +135,7 @@ public class WebSocket extends Transport {
         }
     }
 
-    private String uri() {
+    protected String uri() {
         Map<String, String> query = this.query;
         if (query == null) {
             query = new HashMap<String, String>();