Updated openstack/openstack
Project: openstack/taskflow  1a7de75b1e4dc2040245442319a48a71d7c3dbee

Use the `state_graph.py` for all states diagrams

Switch to using the `state_graph.py` and dot output
as the source of all of the state diagrams (this
makes it easy for anyone to recreate them by just
running the script in the tools directory).

Also update the state diagram creator to have engine
states as well as retry states and replaces all
existing state diagrams with the updated prettified
versions.

Also adjusts some nits around wording and grammar that
were encountered during this updating process.

Change-Id: Ia783aed6c4136763e1e34cbd0b3e57ffb1109abe