Fixes #7750 - hidden required fields do not prevent submit

When a field is explicitly required an HTML5 tag required was added
which caused issues during form submit.
fixes #7737 - no specific logout URL needed, will go directly back to login.
fixes #4672 - added template_name template variable
Fixes #7757 - Fix link_to to call super with block

The original code calls the parent with a single argument: an array of
arguments given to the method. It should call the parent with the
original arguments.
fixes #7477 - new fog prop for IP address in vSphere
fixes #7756 - render not_found.json.rabl for API errors rather than expose too much internal information