conditioning tests on HAVE_ZLIB, etc, just ask libarchive for the
service and handle the failure coming back from libarchive. This
gives us better test coverage of common client usage where clients
simply try to use libarchive services and handle the errors coming
back instead of trying to second-guess which libarchive services are
compiled in.
* support for bzip2 file with multiple concatenated bzip2 streams
* support for bzip2 file with junk after bzip2 stream
* support for gzip file with junk after gzip stream
* "fuzz" tester randomly modifies a bunch of input files in order to try
to crash libarchive (this found an amusing hang in the ISO9660 code
when trying to read images that advertised a zero blocksize).
This test is implemented, but commented out for now:
* support for gzip file with multiple concatenated gzip streams
