Update jquery.noisy.js

New option for disabling the cache.
This to avoid "NS_ERROR_DOM_QUOTA_REACHED: Persistent storage maximum size reached" when trying different settings.
Wrapped the localStorage.setItem in a try statement to avoid the script dying when that does happend.

New option for controlling the range of color channels in use.
This gives you the ability to create brighter and/or darker monochrome noise.