Traverse into archive files

[svogt]

It would be great if veye_checker could traverse into archives.

In the Java world we have EARs, WARs and in case of OSGi also JARs which can include JARs (EARs btw can include WARs which in turn can include JARs ;) ). Also when trying to create an inventory of some product delivery the delivery could be a tar.gz or Zip archive. Would be nice if those could be traversed recursively as well.