#5 Put predicate filter methods in .filters.cs file

[Paul C Smith]

This might be the last major feature for v1: Make the Predicate Filters more usable by automatically creating an .overrides.cs file for the partial Data Access class & persisting them there, instead of making users copy & paste.

For V1, it should only ask once more about overwriting during generation. Later (V2), the collection of predicates could be kept with the object set for comparison to previously generated versions.