Altered title so numbers lined up

the numbers in the matrix did not line up, making it
a bit hard to read.
Documentation improvements. Moved code to filterpy.

Moved the Q_DWPA function to filterpy.

Added help(x) calls for a couple of classes so the docstrings
are displayed in the book. This required me to change the
css style, because it was limiting output to a fairly
short height, and so the help was requiring scrolling.