Figure out what to do with MapFactory

[dannys4]

Currently we have a list of files named MapFactory<k> for <k> in 1 through 15. This will make maintaining the code a bit of a chore, plus most of the code is repeated anyway. Unfortunately, partial template specialization of functions using Enums/ints to distinguish is impossible in C++17 (not that it's gotten any better since). Further, the options may not be known until runtime (e.g. from bindings).

However, we can most likely make a bunch of template specializations, which I think would cut down vs. what we have currently. We definitely could make some preprocessor directives to instantiate the template a bunch of times. Just an idea. Very low priority issue, though.

[dannys4]

neat trick-- you can't do partial template specialization of functions with integers, but you can do them with structs. I can just make a functor class, and then use those partial template specializations as needed.