Review and fixup comments in as-aerchetype pom.xml

The pom.xml contains a few comments that are no longer needed such as "<!-- Timestamp format for the maven.build.timestamp property -->"

The comments should should be reviewed, updates, removed as needed to be clear whether in "enterprise" true or false.

https://github.com/aerogear/as-archetypes/blob/master/jboss-html5-mobile-archetype/src/main/resources/archetype-resources/pom.xml