Put more details about deployments permissions granting into How To Configure Server Security

Book: How To Configure Server Security
Revision: 8001683

Issue description:
Information about granting permissions in section "5.2.2. Defining Policies in the Deployment" should be extended to cover behavior when multiple possibilities are in place.

Suggestions for improvement:

• remove sentence "If a deployment does not have a META-INF/permissions.xml, it will default to the minimum permissions defined by the security mamager subsystem." because the Permissions coming from minimum-permissions are always granted
• add following info: "If both META-INF/permissions.xml and META-INF/jboss-permissions.xml are present in the deployment, then only the permissions requested in the META-INF/jboss-permissions.xml are granted."