Signo support

Added OpenID strategy for Warden, also add configuration and logout
support. When you logout from Katello you are also logout from SSO.

Removed old SSO code that was not used.

Added authentication against Katello that Signo can use.
Fixes for config library

You don't have to specify lambdas for post process if you don't want
to use them. Some other tweaks to make logging library reusable in other
projects.
Katello configure support for Signo

Katello can include more apps in virtual host. Foreman and Signo
will benefit from using same Apache virtual host when running on
same domain. Apache can be used to serve their static files this way.
Install Signo by katello-configure

katello-configure now installs Signo and it's Apache configuration. Once
it's installed it reloads Apache to load Signo vhost config.
Code reviews implementations
Enable fallback to casual authentication

If SSO is enabled but fails we enable to login using the old way. Also
this adds several fixes for edge cases you login in Signo as user that
does not exist in Katello. This could happen if you switched from LDAP
to database authentication in Katello.
Fix code reviews
Loggin fix after merge