Change BinaryXMLEncoder to extend ndn_BinaryXMLEncoder
diff --git a/ndn-cpp/encoding/BinaryXMLWireFormat.cpp b/ndn-cpp/encoding/BinaryXMLWireFormat.cpp
index 83261de..df5ad35 100644
--- a/ndn-cpp/encoding/BinaryXMLWireFormat.cpp
+++ b/ndn-cpp/encoding/BinaryXMLWireFormat.cpp
@@ -27,7 +27,7 @@
   name.get(nameStruct);
 
   BinaryXMLEncoder encoder;
-  ndn_encodeBinaryXMLName(&nameStruct, encoder.getEncoder());
+  ndn_encodeBinaryXMLName(&nameStruct, &encoder);
      
   encoder.appendTo(output);
 }
@@ -59,7 +59,7 @@
   interest.get(interestStruct);
 
   BinaryXMLEncoder encoder;
-  ndn_encodeBinaryXMLInterest(&interestStruct, encoder.getEncoder());
+  ndn_encodeBinaryXMLInterest(&interestStruct, &encoder);
      
   encoder.appendTo(output);
 }
@@ -92,7 +92,7 @@
   contentObject.get(contentObjectStruct);
 
   BinaryXMLEncoder encoder;
-  ndn_encodeBinaryXMLContentObject(&contentObjectStruct, encoder.getEncoder());
+  ndn_encodeBinaryXMLContentObject(&contentObjectStruct, &encoder);
      
   encoder.appendTo(output);
 }