patchwork: Modify patchwork code to handle internal RH instance
    
    The internal RH instance of patchwork has a tweaked API.  Notably it
    embeds a version number into each API call that needs to be filtered.
    
    This adds some logic to autodetect the type of xmlrpc interface using
    the generic pw_rpc_version() call.  This logic was added to
    parse_patchwork_url to help hide the changes from reporter.py.  As a
    result parse_patchwork_url returns with the rpc pointer instead of
    the baseurl.
    
    Further changes includes a 'stringfy' function, copied from our internal
    RH instance.  OVer the years we have learned, email and python enjoy
    delivering text in various forms: ascii, utf-8, iso...  Things always
    break.  stringfy() was our attempt to handle this and reduce all the
    breakage from the strange data formats.  Over the years it was worked
    well.  I use it to wrap patch_get_mbox() (which covers the original
    utf-8 case).
    
    Signed-off-by: Don Zickus <dzickus@redhat.com>