Support HEAD and OPTIONS methods for Browser & AtomPub Bindings

Browser and AtomPub Bindings for Apache Chemistry OpenCMIS and Nuxeo CMIS Connector do not currently support HTTP HEAD and OPTIONS methods. While not as common as the four primary HTTP REST methods, these methods are worthy of support within Apache Chemistry OpenCMIS and Nuxeo CMIS Connector.

Pull request at https://github.com/apache/chemistry-opencmis/pull/6