Patch including new format of changes file, modello backed.
Patch should be backward compatible with previous file format.
TestCases have been upgraded, to check for support of both new and old format.
TODO : test Jira announcement Mojo, to check there is no regression there
TODO: upgrade pom to maven-plugin:2-SNAPSHOT (I don't have maven:2.0.5-SNAPSHOT yet)
TODO: generate a XML Schema (XSD) out of the modello file. We need http://jira.codehaus.org/browse/MODELLO-49 to do this.