Ganeti 2.12 design

The following design documents have been implemented in Ganeti 2.12.

• Ganeti daemons refactoring
• Systemd integration
• Taking relative CPU speed into account
• Instance move improvements

The following designs have been partially implemented in Ganeti 2.12.

• Improvements of Node Security
• HSqueeze tool
• Ganeti OS installation redesign
• Instance Reservations