Add method to parse Messages from xml.

diff --git a/data.py b/data.py
index f0d3d0a..0cc5087 100644
--- a/data.py
+++ b/data.py
@@ -1,3 +1,5 @@
+import xmlserialize as xml
+
 #####################################
 # Some classes

@@ -25,3 +27,7 @@ class Message(object):

     def __repr__(self):
         return "<Message of type %s>" % self.type
+
+    @classmethod
+    def parse(cls, text):
+        return xml.deserialize(text,cls=cls)