Automated anomaly detection

Automated anomaly detection

Compute per-track mean, variance, and n*stddev stats for the first u32
datum in each instance of the supplied event.

Search for the next instance of the indicated event which has a datum
larger than mean + n*stddev.

This turns out to be a very effective "Nixon Gap" finder when the
selected event datum is the instantaneous vector size. Such traces can
be easily captured from production vpp images.

Change-Id: I876843cb2ece22f902720704ce4568d4e1173e01
Signed-off-by: Dave Barach <dave@barachs.net>