Ability to choose to either clean up or keep the last frame of animation after an animation completes

[danielytics]

Right now, the fade animation will retain its "last" frame after the animation completes, but the color-fade animation will reset to a "clean" state. Need the ability to let the user choose which one they want. If keeping the last frame is chosen, also need a way to reset back to a clean state (possibly by running the animation in "reverse").