Better checks and sanitation of the diverse configuration parameters

[tcrivat]

When installing ConPaaS for the first time, many difficulties are caused by the user entering improper or missing values in the different configuration files. This can be counteracted by a more detailed installation guide. However, I think that a simple script that validates the configurations and suggests the user specific actions in solving the possible problems could be of great use.

Some examples of possible configuration problems that are hard to figure out by the user but can be easily checked by a script:

• The OCCI URL contains localhost, so it will only be accessible from the director but not from the managers that run on different VMs. For the user, this causes an error ("Connection refused") when actually starting a service, after the manager was already successfully started.
• The version of OpenNebula that should be used. Version incompatibilities may create different non-suggestive exceptions; the user has no way of figuring out the real problem. This is exacerbated by the fact that the latest version of OpenNebula isn't supported (although it works well if version 3.8 is specified instead).
• The configurations in conpaas/config.php. If this file is missing, the login page is completely empty. If it is present but contains wrong values, the login page is shown but does not contain the actual login form where the user can enter the credentials.
• At least one cloud provider is configured in director.cfg etc. (throws array index out of bounds exception).

[schevalier]

checks to be added on cpscheck, cpsconf, cpsadduser scripts as libcloud, python versions, virtualenv checks or some small last-minute fixes/patches : add-uuid-column-to-db.sh