match: split up main matcher into patternmatcher and includematcher At this point the includematcher is an exact copy of the main matcher class. We will specialize and simplify both classes in the following patches. This initial unmodified copy is just to make the differences clearer. We also rename the main matcher to "patternmatcher" for consistency. I may eventually merge this new includematcher back into the main matcher, but I think doing it this way makes the intermediate steps clearer regardless.