Fixup for changes in tarantool header encoding

The code should follow plain msgpack decode instead of byte twiddling.

Author: sergos

lib/const.js

@@ -21,6 +21,7 @@ const RequestCode = {
 const KeysCode = {
 	code: 0x00,
 	sync: 0x01,
+	schema_version: 0x05,
 	space_id: 0x10,
 	index_id: 0x11,
 	limit: 0x12,

lib/parser.js

@@ -8,11 +8,11 @@ var decoder = new Decoder();
 exports._processResponse =  function(buffer, offset){
   offset=offset||0;
   decoder.buffer = buffer;
-  decoder.offset = offset+23;
+  var size = decoder.fetch();
+  var header = decoder.fetch();
+  var schemaId = header[tarantoolConstants.KeysCode.schema_version];
+  var reqId = header[tarantoolConstants.KeysCode.code];
   var obj = decoder.fetch();
-  var schemaId = buffer.readUInt32BE(offset+19);
-  var reqId = buffer.readUInt32BE(offset+13);
-  var code = buffer.readUInt32BE(offset+3);
   if (this.schemaId)
   {
     if (this.schemaId != schemaId)
@@ -35,7 +35,7 @@ exports._processResponse =  function(buffer, offset){
     }
   }
 	var dfd = task[2];
-	var success = code == 0 ? true : false;
+	var success = reqId == 0 ? true : false;
   if (success)
     dfd.resolve(_returnBool(task[0], obj));
 	else