Updated openstack/openstack
Project: openstack/taskflow  f6d88b0626a3ce3eac04fd7e10d02cc2e9d3d4fd

Add the arch/big picture omnigraffle diagram

To avoid losing this diagram again let's keep
it in the source tree so that others can modify
it and extend it as they desire (and also prevents
it from disappearing).

Will need omnigraffle to view:

https://www.omnigroup.com/omnigraffle

Change-Id: I44eb15722c9d6f2c63d965ff8f849efbdf15bbfb