@output attributes for descriptors and stats objects

Was about to make another thread saying that it would be great to have a @peak flag for fluid.bufloudness~ to optionally not compute the peak of the signal for the second channel output, but this could easily fall under the blanket of an@output attribute as one may potentially be interested in the peak output only, and don’t want the loudness.

This is both in terms of saving a bit of CPU for things you don’t want, but also to have less numbers to prune along the process.

I’m just starting to code the LTE(p) idea from the other thread and I’m over an hour into just trying to figure out what indices/stats I’m interested in moving forward (as well as double-checking the numbers/frames along the way). So far I’ve not even finished the L step…