Merge pull request #516 from HenryOrz/issue515

Some utf8 characters may become "???', if polling is used

src/main/java/com/corundumstudio/socketio/protocol/PacketDecoder.java

@@ -63,7 +63,6 @@ public class PacketDecoder {
             // skip "d="
             packet = packet.substring(2);
         }
-        packet = new String(packet.getBytes(CharsetUtil.ISO_8859_1), CharsetUtil.UTF_8);
 
         return Unpooled.wrappedBuffer(packet.getBytes(CharsetUtil.UTF_8));
     }
@@ -136,9 +135,6 @@ public class PacketDecoder {
             int len = utf8scanner.getActualLength(buffer, lenHeader);
 
             ByteBuf frame = buffer.slice(buffer.readerIndex() + 1, len);
-            if (lenHeader != len) {
-                frame = Unpooled.wrappedBuffer(frame.toString(CharsetUtil.UTF_8).getBytes(CharsetUtil.ISO_8859_1));
-            }
             // skip this frame
             buffer.readerIndex(buffer.readerIndex() + 1 + len);
             return decode(client, frame);