Add XML payload support

Fixes #238

vendor/github.com/clbanning/mxj/gob.go

@@ -0,0 +1,35 @@
+// gob.go - Encode/Decode a Map into a gob object.
+
+package mxj
+
+import (
+	"bytes"
+	"encoding/gob"
+)
+
+// NewMapGob returns a Map value for a gob object that has been
+// encoded from a map[string]interface{} (or compatible type) value.
+// It is intended to provide symmetric handling of Maps that have
+// been encoded using mv.Gob.
+func NewMapGob(gobj []byte) (Map, error) {
+	m := make(map[string]interface{}, 0)
+	if len(gobj) == 0 {
+		return m, nil
+	}
+	r := bytes.NewReader(gobj)
+	dec := gob.NewDecoder(r)
+	if err := dec.Decode(&m); err != nil {
+		return m, err
+	}
+	return m, nil
+}
+
+// Gob returns a gob-encoded value for the Map 'mv'.
+func (mv Map) Gob() ([]byte, error) {
+	var buf bytes.Buffer
+	enc := gob.NewEncoder(&buf)
+	if err := enc.Encode(map[string]interface{}(mv)); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}