Clarity: a module to enhance Rack UX

@contemporaryinsanity — I take back what I said about not being able to reproduce it. I can, and it is now fixed.

Thank you for coming back with a second report instead of letting it go. I missed it at first because it depended on the number of modules in the patch, and I was testing with only a few modules but it was a check that ran on the audio thread for every module. Now the check is off the audio thread completely.

The fix is in the repository and will be in the next release.