Synnefo

Update admin-guide about RabbitMQ

Update admin-guide about managing VMs

Update admin-quide with links to quick-admin

More fixes to Admin Guide

Update docs with Ganeti backend handling

Update docs about bridge/mac-prefix pools

Sphinx fixes

Update guides to reflect new Astakos defaults

• ReCAPTCHA is no longer enabled by default
  (move from Quick Install Guide to Admin Guide)
• Only the 'local' IM module is enabled by default
  (no need to set it during Astakos configuration any more)

Add target directives to documentation images

In guide, set ASTAKOS_DEFAULT_ADMIN_EMAIL to None

This way the user doesn't have to set up an email server.
Add a new section in `admin-guide' named mail-server.

Add mail server variables in admin guide

Move Shibboleth documentation

Move the documentation concerning Shibboleth authentication to a
dedicated section inside the Admin Guide. Shibboleth targets advanced
users only, so it should not reside inside the Quick Install Admin
Guide.

Add Astakos "Terms of Use" documentation

Major documentation refactoring

Merge documentation of different components and services
all together. Target to a generic, unified, robust
documentation tree.

This is WIP