Add the verification protocol

This adds a verification protocol to the database which allows the database to be used in vulnerability analysis experiments.

We do so several things to create a verification protocol:

• We will create a model for all clients. In the licit scenario:
• We will use the laptop samples for enrollment and mobile samples for probe.
• We will probe all clients against each other. In the spoof scenario:
• We will use the laptop samples for enrollment and all attack samples for probe.
• We will use only the enrolled client's attacks for probes.