avoid using Array.apply(new Array(), buf) for compatability

lib/encoding/bufferwriter.js

@@ -87,8 +87,7 @@ BufferWriter.prototype.writeUInt64BEBN = function(bn) {
 
 BufferWriter.prototype.writeUInt64LEBN = function(bn) {
   var buf = bn.toBuffer({size: 8});
-  var reversebuf = new Buffer(Array.apply(new Array(), buf).reverse());
-  this.write(reversebuf);
+  this.writeReverse(buf);
   return this;
 };