diff transforms/percussiononsets-detectionfunction.n3 @ 123:b514bae9555e

Do not feed audio data to a plugin before its transform's start time (we might be feeding other transforms that started earlier). This breaks a test, but the test's expected output was broken (rather alarmingly)! Note that this does mean a plugin may have to-next-block "leakage" at start as well as end of its start-duration zone.