bug#17853: GLib references Python

[ludo@gnu.org (Ludovic Courtès)]

As of v0.6-441-gfe6e3fe, GLib keeps a reference to ‘python-wrapper’,
because of two scripts:

--8<---------------cut here---------------start------------->8---
$ grep /bin/python /gnu/store/l4yvfmp8ys2xjkmrvcxzdlx86qzlishr-glib-2.39.1/bin/*
/gnu/store/l4yvfmp8ys2xjkmrvcxzdlx86qzlishr-glib-2.39.1/bin/gdbus-codegen:#!/gnu/store/z36w7wiz6vqqcpridw03afkq68cm5rhh-python-wrapper-3.3.5/bin/python
/gnu/store/l4yvfmp8ys2xjkmrvcxzdlx86qzlishr-glib-2.39.1/bin/gtester-report:#!/gnu/store/z36w7wiz6vqqcpridw03afkq68cm5rhh-python-wrapper-3.3.5/bin/python
--8<---------------cut here---------------end--------------->8---

This is a problem because that means that, say, Avahi, pulls in all of
Python 3, which is quite big.

The solution may be to add a “bin” output.

Ludo’.