[DRAFT] Fake data for mocks

[ProtocolNebula]

The mock engines should be capable of use a fake data generator.

The generator can be chosen by the user using a parameter.
Also, fake data generators can be written like a mock engine, so can be developed outside the application.

Alternative (and easier) option:
Provide a YAML/JSON file which specifies for each "Model" and "Parameter" a list of possible values, so you can create a "set" of data to be generated on each upgrade.

The non-specified parameters will be generated like now (example/default/random)