Add Statistical Flow

[capn-freako]

PyBERT has, since its inception, been a time domain simulator.
It generates a sequence of random bits, using a PRBS generator, and runs those bits through its system model, using convolution for the LTI portion and sample-by-sample adaptive processing for the CDR/DFE.

Let's add a purely statistical analysis, to provide a comparative reference for our time domain results and to be more consistent with the commercial offerings.

A wonderfully detailed and complete reference for this is provided by Dai, et al..
See Sec. 5 and, more specifically, (5.5) thru (5.8).

[capn-freako]

Can the new PyChOpMarg package be used here, to avoid redundant work?