[session] move context manager logic in the security context manager
The `init_security` and `reset_security` method have no other user that the context manager itself. Having dedicated public function is not useful.
#! /bin/sh -e
#
if [ "$1" = configure ]; then
if which install-docs >/dev/null 2>&1; then
install-docs -i /usr/share/doc-base/cubicweb-doc
fi
fi
#DEBHELPER#
exit 0