Move some variables out of GiraffeDraw object
Move some variables out of GiraffeDraw object

Giving them "package scope" saves space
UndeadBlow/giraffe,BjornFJohansson/giraffe,BjornFJohansson/giraffe,BjornFJohansson/giraffe,BjornFJohansson/giraffe,UndeadBlow/giraffe,addgene/giraffe,addgene/giraffe,BjornFJohansson/giraffe,addgene/giraffe,addgene/giraffe