Order of arguments is inconsistent between Tween constructors, Timeline add() functions

[WesWedding]

Making the method signatures more uniform is a good thing; I'm sure it would be easy to inflict confusing behavior on devs who use a mix of

TweenDuino::Tween* addTo(float& target, float to, unsigned long duration) and Tween *to(float& target, unsigned long duration, float to) in their code.

This will be addressed (partially, if not completely), when #11 is addressed.