Track performance with onionperf, if we can
We need to start tracking performance while we're doing our 0.1.0 milestone, so that we're ready to start improving it in 1.0.0.
This ticket was originally about doing a bare minimum of performance work in 0.1.0, but it grew into a discussion of what we'd need to do in order to measure Arti with onionperf. Now that we have arti-bench, it's no longer a necessity for 0.1.0, but we would like to have onionperf integration at some point.
Edited by Nick Mathewson