In the documentation and the printed messages, remove all references
to ~okeanos, pithos or cyclades.

Make the ChangeLog comply with the latest changes

Update the documentation to reflect the changes made after 0.2.4

The example has been copied from okeanos-guides. However, some
of the example's steps have been ommited (e.g. the installation of
snf-image-creator). Also, the focus has been shifted from ~okeanos to a
run-of-the-mill synnefo deployment.

Add missing sections