implement ability to retrieve packaging handlers (lifecycle mappings) from extension plugins. Remove plugin mapping
metadata for the same
integration tests are in place for type handlers but commented out until implemented (41)
git-svn-id: https://svn.apache.org/repos/asf/maven/components/trunk@225263 13f79535-47bb-0310-9956-ffa450edef68
o Fixing core-library resolution for expression: ${plugin.artifacts} and ${plugin.artifactMap} (latter is keyed by g:a)
o Modified maven-core-it-plugin to accept something like "-DartifactToFile=org.apache.maven:maven-artifact"...it'll lookup that artifact in ${plugin.artifactMap}, and touch a file that's a mutation of the abs. path for that artifact.
o Added pomArtifact to ResolutionGroup, since the MavenMetadataSource ALWAYS creates a new Artifact for a pom...this allows us to retrieve the resolved Artifact for that pom.
git-svn-id: https://svn.apache.org/repos/asf/maven/components/trunk@225234 13f79535-47bb-0310-9956-ffa450edef68