It was discussed after the class in Boston that we might want
to add something about 'Work In Progress' patches in the
workflow section somewhere. After looking through the content the
best place to put it seemed to be in the 'Reviewing' section as
that allowed to tell how a 'WIP' could be indicated and then how
that should be handled from a review standpoint.
This patch adds a couple of slides to cover the topic.
Change-Id: Icf77b248e4cfddf1d6efd5fa1d8b0a94fefdc76d