Fix bug: I/O operation on closed file.

After upgrading Python to Debian package version 2.7.5-7 I started receiving
errors: "I/O operation on closed file" when opensub-get tried to read the
subtitles from the archive.

It looks like that the eager behaviour of zip() led to yield()-ing multiple
file objects open at the same time from the zip archive which is not
supported by zipfile.
Update version file.
Fix bug: setup.py needs to be run from src/.
Update version file.