Revision 224413

Working on MNG-607

o Changed MavenMetadataSource to a component, to avoid having to lookup artifactFactory and projectBuilder in order to 
  construct it.

o Added add(..) method to ScmBean in the release plugin to allow addition of release-pom.xml

o Changed the PrepareReleaseMojo to resolve ONLY version and parent-version for the normal pom.xml, and fully resolve all
  artifacts used in the release-pom.xml, including version, parent-version, dependency closure (given by project.getArtifacts()), plugins, and reports. It will then add the release-pom.xml, and (attempt to) delete it before performing the final commit for next development version.

o Added some mapping methods to ArtifactUtils, to key by artifact.getId, and to create an Artifact.getId()-compatible string from parameters.

o Added TestProjectBuilder to remove the requirement in ProjectClasspathTest to modify the fields of the project builder directly.

o Cleaned up the AbstractReleaseMojo and PrepareReleaseMojo to avoid container lookups...they're now mojo parameters with the 'component.' prefix.

NOTE: Next step is to figure out how to use maven-scm to remove an SCM resource, to enable the prepare mojo to take the release-pom.xml back out of HEAD after the tag is complete.