Some people might be confused and think it is paths

"I remember it is something scary ;)"

@jm noticed downloading arhives in tar.gz format was failing. Details are in second patch.

/cc @lab.nexedi.com

/reviewed-on nexedi/slapos!70

fix publish custom frontend url
simplify monitoring connection parameters

/reviewed-by: TrustMe

This causes Cloudooo to not listen anymore.

/reviewed-on !75

* now glib is built with our own pcre.
* libsigc++, glibmm, pangomm and atkmm are kept in older version because glibmm >= 2.46 requires C++11 compiler.

  The password and username has to be passed to the others instances and used

Define a simple cache implementation using a Dict (Singleton) to prevent call registerComputerPartition
  multiple times over the sections.

/reviewed-on nexedi/slapos!74