Fix entrypoints being updated/created by update.py

Previously entrypoints were not being created in the
target projects setup.cfg which means that the target
project would not be able to correctly use the taskflow
provided entrypoints. To fix this add a new helper
function to update.py that alters the entrypoint and
creates (or updates) the setup.cfg file where those
entrypoints are defined.

Fixes bug: 1235988

Change-Id: Ie32324c88e3c3642e58f3532e868f171f973d15e
Merge "Fix entrypoints being updated/created by update.py"
Add reasons as to why the edges were created

Reasons are useful for later analysis when running
as to why the edge between two nodes was created so
when linking items in the graph it would be nice to
assign a reason.

Change-Id: I2185cf5fb3c2c07c0f5536d3b210080c6f61d5dd
Remove decorators and move to utils

In order to avoid the circular import
in threading utils move the decorators
functionality to utils/misc and move the
locking functionality to utils/lock_utils
and then use these functions from the
threading util (and elsewhere).

Fixes bug: 1236080

Change-Id: I9e71c2ba15782cbb6dd5ab7e1264b77ed47bc29e
Merge "Remove decorators and move to utils"
Add a set of useful listeners

In order to understand how listeners are used it is pretty
nice to have a default set that do basic printing and logging
that can be used in debugging (or just as examples).

Include an example that uses this as well.

Fixes: bug 1224060

Change-Id: I7ba6e9dcbdca84d014b9d1f5054ce7a37eb766f2
Merge "Add a set of useful listeners"
Add a example which uses a sqlite persistence layer

Add an example that will use a sqlite layer for
persisting flow and task information, and will use
the layer for future resumption.

Show how to output what a logbook contains as well.

Change-Id: If5f936fe100cb43ed857b99e3fae0c6e6baba5ed
Add a simple mini-billing stack example

Change-Id: Idf9a7b57935298d347738df9c7f7002379dbfde2
Merge "Add a simple mini-billing stack example"
A few wording/spelling adjustments

Change-Id: Id77c7983d7d03319ffcb945268cb972ae53552b6