mtest 0.7.2

• Each call measured by itself (bench::each, mcpplibs.mtest.bench). bench::measure times
  batches and states what one call costs on the whole; each times every call, for work whose
  calls differ and whose slow ones are the point -- a frame, a request, a step of a simulation. It
  reports where the calls lie as metrics a bound can name: the median as name, and name.p95,
  name.p99, name.max, name.mean (at_most{"draw.p95", 0.016}). The body may take a
  bench::lap: pause() and resume() leave out what is not the call's (preparing the next
  input), items(n) states what the call worked through and adds name.per_item. The samples are
  not stated with these metrics: the verdict on samples that spread is for a measurement meant to
  be one number. bench::distribute and bench::percentile are the same arithmetic on samples a
  test has already. Additive; no event and no clause changed.