Add vibration customization

[vertigo220]

First I just want to say this is a really neat little app which is very well done. I ran across it searching for something else and am glad I did, as it's the next best thing to a camera shutter.

The one thing I've found that could use some improvement is the vibration when an app uses the camera or mic. It's extremely short and weak, so it's unlikely I'd ever notice it, as I barely did even when testing it. It would be much better if it could be customized, at least duration and intensity, but possibly pattern as well.