Updated Filesystem deployment scanning

Implement changes described at http://community.jboss.org/message/572083#572083

I'm going to create a separate subtask for the issue of a flag on the deployment repository config to remove the requirement for a .dodeploy file on an exploded deployment and instead support the legacy behavior of touching the standard deployment descriptor in META-INF. That is more of a nice-to-have and shouldn't block implementation of the rest.