new docs WIP

new docs WIP

This WIP is part of the final push for 1.4's docs
to fully "2.0-ize" what we can, and have it all ready.

So far this includes a rewrite of the 2.0 migration,
set up for the 1.4 /2.0 docs style, and a total redesign
of the index page using a new flex layout in zzzeeksphinx.

It also reworks some of the API reference sections
to have more subheaders.   zzzeeksphinx is also enhanced
to provide automatic summaries for all api doc section.

Change-Id: I01d360cb9c8749520246b96ee6496143c6037918