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

--- a/docker/jp/Dockerfile	Sat Feb 27 00:45:58 2016 +0100
+++ b/docker/jp/Dockerfile	Sun Feb 28 02:01:20 2016 +0100
@@ -14,15 +14,14 @@
 # BASE #
 ########
 
-RUN apt-get install -y --no-install-recommends python-progressbar
-RUN apt-get clean
+RUN apt-get install -y --no-install-recommends python-progressbar && apt-get clean && \
 
 #########
 # D-Bus #
 #########
 
 # we create a wrapper to set the session bus address
-RUN cp /usr/local/bin/dbus_wrap /usr/local/bin/jp && chmod 0555 /usr/local/bin/jp
+cp /usr/local/bin/dbus_wrap /usr/local/bin/jp
 
 ##########
 # LAUNCH #