Manifest sections are only added to the manifest when the archive is created

Maven Assembly Plugin uses a MavenArchiveConfiguration object to get the configuration from the POM. Then it uses MavenArchiver.getManifest( MavenProject, MavenArchiveConfiguration ) to create a manifest. This is then fed into PlexusArchiver. Currently Maven Archiver adds Manifest Sections to the manifest Object only if an actual archive is created. So Maven Assembly Plugin doesn't get this part of the configuration. I don't see any reason for keeping this part from the user until they create an archive.