ACE support in windows

[dadokkio]

Hi,
we needed to open ACE archive on a windows platform but we had some problem.
In detail we had to install peazip with ace add-on (in order to have unace.exe) and then edit the extract_ace function in unace.py.

Default code output was:

>>> x = patoolib.extract_archive("pippo.ace", verbosity=1, outdir=".")
patool: Extracting pippo.ace ...
patool: running "C:\Program Files\PeaZip\res\unace\unace.exe" x pippo.ace ./
Info: creating file list

Error: no files specified
Info: finished creating file list

ActiveACE operation return code: 2
patool: ... pippo.ace extracted to .

We had to change the x flag to e [extract in current folder] and remove the output folder

def extract_ace (archive, compression, cmd, verbosity, interactive, outdir):
    """Extract an ACE archive."""
    return [cmd, 'e', archive]

>>> x = patoolib.extract_archive("pippo.ace", verbosity=1, outdir=".")
patool: Extracting pippo.ace ...
patool: running "C:\Program Files\PeaZip\res\unace\unace.exe" e pippo.ace
Info: creating file list
Info: adding file to file list
Info: finished creating file list
Extracting pippo.ace

  Extracting pippo.txt  (12 byte uncompressed, 12 byte compressed)
    processed: 0 of 12 bytes (0 of 12 bytes)
    processed: 0 of 12 bytes (0 of 12 bytes)
    processed: 0 of 12 bytes (0 of 12 bytes)
    processed: 12 of 12 bytes (12 of 12 bytes)
   CRC OK

ActiveACE operation return code: 0
patool: ... pippo.ace extracted to `.'.

There is a better way to proceed?