Many changes to get this to pass on Windows, and to make it easier to

Many changes to get this to pass on Windows, and to make it easier to
figure out what the code was doing.  The fixes were a combination of
closing open files before deletion, opening files in binary mode, and
plain skipping things that can't work on Windows (BaseTest.decompress
uses a process gimmick that doesn't exist on Windows, and, even if it
did, assumes a "bunzip2" executable is on PATH).