Add a stop generating waves to the wave modifier

One of the problems with the wave modifier (at least that I know of) is the lack of a button like in most other things for stopping the generation of waves (like how fluid sims have use flow.) Basically a button which would be called "generate waves" and when checked it would make the waves but if unchecked with a keyframe halfway through the animation then the waves present would finish doing there thing and then no more would generate. This lack of a feature is particularly annoying when you need to have waves that only last a few waves but there is no way to stop the generation without removing current waves. Please fix and thanks