KEYCLOAK-795 Move Auth Server into Keycloak Subsystem

Support auth-server running in a WildFly domain.
Eliminate deployment from /deployments directory to make it a proper service instead of an ordinary app.
Eliminate need to explode or crack open auth-server.war. Keep it intact so it doesn't need to be hacked up.
Allow uploading provider jars and keycloak-server.json overlays from CLI.
Allow more than one auth-server in a WildFly instance.

Note: EAP6 support not implemented in this PR.