GitLab

add network state tag
improve public ip vm tag

Initial documentation concerning Cyclades installation.
Add prerequisites sections, needed before the actual Cyclades
installation section:

 * General Prerequisites
 * Setting up Ganeti
 * Installing/Configuring/Testing snf-image
 * Uploading snf-image Images on Pithos+
 * Connecting Ganeti with Pithos+ and spawning VMs from those Images

Networking section will follow. This is WIP

mock astakos get_user to bypass calls to astakos server

 * Update the Message Queue installation on node1
 * Update the "Testing of Pithos+" section
 * Minor other fixes

include Changelog chapter in main document for cyclades-app and
webproject

Refs #2358

 * Point out how to install gunicorn from backports
 * Fix typos

so that sphinx autodoc extension can access plankton source files