Summary: zip filesystem provider update, add zipfs.jar into ext dir
Reviewed-by: alanb

6994161: (zipfs) newFileSystem method should FileSystemAlreadyExistsException
6994152: (zipfs) copyTo ignores COPY_ATTRIBUTES option
Summary: zipfile update
Reviewed-by: alanb

Summary: The first drop of the zip filesystem provider, as a separate demo
Reviewed-by: alanb