Fixed previous patch for delay_adjust( $id, 0 ), which means the delay happens now.
Crudely benchmark the machine under test.

A lot of POE's tests work around slow machines by unconditionally
delaying a lot.  This makes the tests feel ponderous on fast systems,
and it thwarts Continuous Integration.

Benchmarking machines under test will help me tell how much the
work-around is needed.  It may eventually hint to other tests how long
they need to wait.