Property access instead of getters/setters

I’m massively in favor of this. It may not be obvious to people who are primarily C++ coders, but Panda3D syntax often feels antiquated and crufty to me. I honestly can’t remember the last time I used another library that used getter and setter functions.

Edit: Not to be critical! Panda3D is awesome. I’m just hoping it continues to embody “pythonic” practices, like these properties.