Introduce noop vars plugin.

In preparation to move the group_vars plugin code into core.

	new file:   lib/ansible/inventory/vars_plugins/noop.py

lib/ansible/inventory/vars_plugins/noop.py

+# (c) 2012-2014, Michael DeHaan <michael.dehaan@gmail.com>
+# (c) 2014, Serge van Ginderachter <serge@vanginderachter.be>
+#
+# 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/>.
+
+class VarsModule(object):
+
+    """
+    Loads variables for groups and/or hosts
+    """
+
+    def __init__(self, inventory):
+
+        """ constructor """
+
+        self.inventory = inventory
+        self.inventory_basedir = inventory.basedir()
+
+
+    def run(self, host, vault_password=None):
+        """ For backwards compatibility, when only vars per host were retrieved
+            This method should return both host specific vars as well as vars
+            calculated from groups it is a member of """
+        return {}
+
+
+    def get_host_vars(self, host, vault_password=None):
+        """ Get host specific variables. """
+        return {}
+
+
+    def get_group_vars(self, group, vault_password=None):
+        """ Get group specific variables. """
+        return {}
+