Provide AndHow method to print samples

Printing samples is a little dangerous because it can write the current values to a location where it could be read. Perhaps rogue code could even request it, then read the output.

This probably needs to happen as part of startup and be blocked happening anywhere else. It could also be part of the NonProductionLoader, but rogue code could use the NPL and cover its tracks.

At a minimum, the password Property type should be added before this is done. Perhaps `Property` needs an `printToString` method that would not print secrets.