reorder pom to put main versions we track at the top
convenience for getting brooklyn maven urls
better control over updating controllers synchronously v asynchronously, plus minor tidies
working archetype, plus notes
move maven-artifact routines out to new classes e.g. BrooklynMavenArtifact,
and use this in demo app to get a reliable WAR download;
also use this for JMX support (and use that for additional testing!)
which has nice benefit that JMXMP installation works from IDE even when
JAR has not been copied across