Fix broken flake8 configuration and flake8 errors which were hidden by this breakage. flake8 --filename options doesn't work as expected: * it's expected to be a shell pattern, using stdlib's fnmatch.fnmatch function internally. This funciton thinks that 'cubicweb/x.py' doesn't match 'cubicweb/x.py' (there must be a reason but that's not the point), hence no file was actually checked ; * as this is a list of pattern, each encountered file is checked against each pattern, leading to run time explosion. So maintain list of files to check in a separated file and give this list to flake8 using unix's xarg command.

#! /bin/sh -e
 
case "$1" in
    remove)
	if [ -x "/etc/init.d/cubicweb-ctl" ]; then
	    invoke-rc.d cubicweb-ctl stop || true
	fi
    ;;
esac
 
#DEBHELPER#
 
exit 0