Jar archive descriptor

Hi Dirk,
can you have a look at this. I changed the JarScannerPlugin so that it is creating a JarArchiveDescriptor for every jar file it scans. The name of the node matches the name of the scanned file. The contents of the jar file are added to the JarArchiveDescriptor node by a CONTAINS relation.
There is a global variable in JarScannerPlugin. This only works if a JarScannerPlugin is not reused by different scans. I'm not seeing a way to avoid the global variable here.
Btw. My formatting settings don't match yours. Could you make your settings available?
Maybe we could avoid this is AbstracthArchivScannerPlugin enfores a method getArtifact()?