cleanup Modifier, Predicate and Score method names

[drussel]

eg for Score

• evaluate that is overloaded to take indexes and particles
• do_evaluate that is the implementation (and calls evaluate_index by default) and takes indexes
• evaluate_index that is there for backwards compat to be overloaded _METHODS macro can define what is needed.

That way we can implement things in python and C++ and don't have to switch names based on what it is being called with.