Feature Request: Resolve setters at beginning and reuse during tween

[TomByrne]

Actuate uses Reflect.setField / setProperty to set tweened values in.

This is very expensive on some targets (as Error objects are constantly allocated) and hides any errors produced within the setter. Ideally, the GenericActuator would work out whether a property should go through a setter once at the beginning of a tween, and then either use this setter or directly set the field in an untyped manner (without a try/catch).