HISTORY and setup.py updates for tagging v0.12

HISTORY

 2013-01-25
+v0.12 - PolicyIterationModified has been completed and is feature complete. Unit tests have not yet been written, and the docs need fixing.
+	>>> import mdp
+	>>> P, R = mdp.exampleForest()
+	>>> pim = mdp.PolicyIterationModified(P, R, 0.9)
+	>>> pim.iterate()
+	>>> pim.policy
+	(0, 0, 0)
+
 v0.11 - QLearning is now ready for use in the module, with a couple of unit tests already written. The class is used as follows:
 	>>> import mdp
 	>>> import numpy as np

setup.py

@@ -3,7 +3,7 @@
 from distutils.core import setup
 
 setup(name="PyMDPtoolbox",
-      version="0.11",
+      version="0.12",
       description="Python Markov Decision Problem Toolbox",
       author="Steven Cordwell",
       author_email="steven.cordwell@uqconnect.edu.au",