Add filter to turn a string into a UUID

This filter was made because I needed to create idempotent UUIDs when
installing the agent for Go (http://go.cd), which uses UUIds to
distinguish the agents from each other.

It uses a newly created Ansible namespace to distinguish UUIDs created
by Ansible from any other source. The new namespace is a random one
created by uuidgen on OSX.

test/units/TestFilters.py

@@ -131,6 +131,11 @@ class TestFilters(unittest.TestCase):
                                                       'a\\1')
         assert a == 'ansible'
 
+    def test_to_uuid(self):
+        a = ansible.runner.filter_plugins.core.to_uuid('example.com')
+
+        assert a == 'ae780c3a-a3ab-53c2-bfb4-098da300b3fe'
+
     #def test_filters(self):
 
         # this test is pretty low level using a playbook, hence I am disabling it for now -- MPD.