Setting appropriate executable permissions

[Rick Barrett]

It looks like maybe on Macintosh the proper permissions aren't getting set when the zip files are extracted. This is particularly affecting clipAICBHandler in CV-ArtSmart.

It might just be a matter of setting zipinfo.create_system as here: https://mail.python.org/pipermail/pythonmac-sig/2005-March/013491.html

See also here: http://stackoverflow.com/questions/3007233/preserve-file-attributes-in-zipfile

[Rick Barrett]

Maybe this:

unix_attributes = info.external_attr >> 16
+            if unix_attributes:
+                os.chmod(target, unix_attributes)

[Rick Barrett]

Fixed in 95a7eb16519159d3195478ced1caeaa8f08db6f4