Theme: dialog and scene are not instance vars
MixStream: properly clamp samples that clip
Clean up drawImage a bit by merging its features into ImgDrawing methods and move drawImage into a static ImgDrawing method
Make a global method for parsing of a String's value is equivalent to True
Fix some bug with shader loading from Themes and Config if the key isn't defined
Fix a few things that broke along the way when a song doesn't have a loading background.
Fixed this by making drawImage return True when the image is drawn and False when you don't give it a proper image instance