New module 'set_fact' to define host facts

This module allows you to set host facts (or export play variables to the playbook scope if you fancy that).

The module also accepts complex arguments.

```yaml
 - action: set_fact fact="something" global_fact="${local_var}"'
 - action: set_fact
   args:
      fact: something
      global_fact: ${local_var}
```

lib/ansible/runner/action_plugins/set_fact.py

@@ -0,0 +1,37 @@
+# Copyright 2013 Dag Wieers <dag@wieers.com>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+from ansible import utils
+from ansible.runner.return_data import ReturnData
+
+class ActionModule(object):
+
+    NEEDS_TMPPATH = False
+
+    def __init__(self, runner):
+        self.runner = runner
+
+    def run(self, conn, tmp, module_name, module_args, inject, complex_args=None, **kwargs):
+        ''' handler for running operations on master '''
+
+        # load up options
+        options  = {}
+        if complex_args:
+            options.update(complex_args)
+        options.update(utils.parse_kv(module_args))
+
+        return ReturnData(conn=conn, result=dict(ansible_facts=options))