docker: images optimisation: - reduced the number of layers by grouping many instructions - moved stuff which don't change a lot at the beginning, and hg/apt at the end - scripts are not now in scripts/ subdirectories - prosody.cfg.lua is added using ADD instead of getting it online - .hg/dirstate is copied in base (backend) and libervia, so mercurial revision is known - removed lot of useless WORKDIR instruction, they are replaced by "cd" inside RUN instructions - cleaning (apt-clean, rm) is done on the same instruction as the one than generate the data, to avoid useless data in layers

#!/bin/sh
# this script will launch the command with good D-BUS parameters
# it needs to be copied and made executable by frontends
export DBUS_SESSION_BUS_ADDRESS=tcp:host=sat,port=55555,family=ipv4
exec /usr/bin/$(basename "$0") "$@"