Rewrite to Godot3!

In the middle of rewriting to port Fursona Creator to Godot3 ^^

It's not done yet, but I figured I'd push what I've done so far because I'm tired and am unlikely to finish this soon. Hopefully you'll agree that everything looks neater - in particular you can now resize the window and everything scales properly. I'm also nearly ready to put in beak recolouring, so look forward to that soon!