Bug#944113: please emit an error for python shebangs used in a package

[Matthias Klose <doko@debian.org>]

Package: lintian

Issue #943366 asks to split out the request to emit an error for python shebangs 
used in a package into a separate bug report.

This should include usage of python in autopkg tests, and maybe rules files, if 
it's detectable.

#943666 has the discussion about changing the Python policy about this.