flatpak: update build-manifest to retrieve dependencies without initial download phase: - dependencies are now entirely retrieved from the installation, and requirement are build from there. The source package is currently always used, and it is now possible to use PYTHON_DEP_PREINSTALL to add extra packages or use a specific version of a package. - fixed insertion of `release_elt` for dev version at the right location. - `branch` is not set anymore for stable versions. - libxslt is not added anymore as it is part of freedesktop runtime - flathub share-modules is now used for Python 2

#!/usr/bin/env python2
# This script launch Salut with domain and secret gotten from prosody container
# it make the configuration more easy
import os, xmlrpclib

SALUT_PATH="/usr/share/sat_salut/"
os.chdir("/home/sat")
proxy = xmlrpclib.ServerProxy("http://prosody:9999/")
for var in ("DOMAIN", "SAT_SALUT_SECRET"):
    os.environ[var] = proxy.getenv(var)
os.environ["PYTHONPATH"] = SALUT_PATH
os.execlp("twistd", "twistd", "-ny", SALUT_PATH+"salut.tac", "--pidfile", "/tmp/salut.pid")