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/sat/Dockerfile	Sat Feb 27 00:45:58 2016 +0100
+++ b/docker/sat/Dockerfile	Sun Feb 28 02:01:20 2016 +0100
@@ -14,20 +14,8 @@
 # Ports #
 #########
 
-# IMAP
-EXPOSE 10143
-
-# SMTP
-EXPOSE 10125
-
-# FILE TRANSFERT
-EXPOSE 28915
-
-##############
-# PROSODYCTL #
-##############
-
-RUN chmod 0555 /usr/local/bin/prosodyctl
+# IMAP, SMTP and FILE TRANSFER
+EXPOSE 10143 10125 28915
 
 ########
 # MISC #