Update JSF APIs to Specification Version 2.1

The git repo is set up for the JSF API to move to v 2.1:

https://github.com/jboss/jboss-jsf-api_spec/

Note, too, with the adjusted parent pom, the APIs will be compiled using JDK 6 as default. Due to that, I've changed the
version of this artifact to start with 2.0.0-SNAPSHOT.