Enable audits of trained models

[LiFaytheGoblin]

• make sure trained models are excluded for the current process
• allow trained models to be audited by using the current process, but make users aware that the audited model is just ONE version of the trained model, where some of its training data is used instead as testing data.
• allow trained models to be audited without re-training, by enabling and use of test data (depends on Enable users to provide own datasets #17)