Use a TRUST_FINGERPRINTS file to decide which p4 trust fingerprints to accept.
If we receive a request that is *not* in this file, and this setting is used, we reject it. This is our recommendation for production servers.
The ENABLE_AUTOMATIC_TRUST is only to be used for testing servers. We need this because of a high-cost of the Qt test framework.
Revised upon request of Alan Teague and Doug Scheirer.