Revision 215890

Fixing issues related to MNG-377, where the plugins.xml metadata was being mishandled. Separated updating of this metadata into a separate mojo, bound to the 'package' phase, and put in a validator for the POM (POM has to have distributionRepository now for maven-plugin's) which is bound to the 'validate' phase. Put together an integration test that uses modello:java as a case where the pluginGroups must be consulted. Also had to change the Verifier to check a verifier.properties for failOnErrorOutput, which will suppress IT failures based on [ERROR] log output (modello outputs one of these, and kills the IT unnecessarily).

MNG-377 should be resolved at this point.