Gives users a more permanent way to provide an initial set of
arguments to a flow.

Change-Id: Ib9c3d60882548120d467a645bbac9be78408bac3
Implements: blueprint flow-details-keep-store

It appears folks are using the taskflow.utils code in there own
code-bases (likely taking it from the examples) which we do not
want to encourage, so remove the usage of **most** of
taskflow.utils code from the examples so that people are less
likely to copy/paste/reference it.

Change-Id: I0ce3c520de347e3e746e7912aa1366a515458424

Since this module contains more than the logbook
class and really is a our generic models that are used
to hold the runtime structure it is more appropriate to
place it under a models module and deprecate the usage
of the old module by placing a warning there (so that
when it is imported that warning is triggered).

Change-Id: I79def5ee08f560d38f2c9dcefd0b33becc2a4d36

Prefer the non-deprecated 'oslo_utils' instead of
the namespaced 'oslo.utils' wherever it was previously
used.

Change-Id: I9a78150ef5266e1ff22147278162fe3cfe1b2e3f

To at least try to support things like windows it's better
if we can make an attempt to use the platform neutral
characters for line separator(s) where appropriate.

Change-Id: Icc533ed4d4c94f461b7f19600b74146221f17b18

The reflection module is now part of oslo.utils so we should
remove our local version and use that version instead; this
also goes for the uuidutils module which is now part of
oslo.utils as well so we no longer need our local version
copied from the incubator...

Note that one reflection method `find_subclasses` which was to
specific to taskflow is now moved to the misc utility module
instead of its prior home in the reflection module.

Change-Id: I069881c80b0b2916cc0c414992b80171f7eeb79f

Add a new logging BLATHER level to easily allow its
usage for messages that are below the normal DEBUG level
such as compilation information and scope lookup info
which can be very verbose in logs if always enabled.

Change-Id: I828211403bd02bfd6777b10cdcfe58fb0637a52c

Instead of copying modules from the incubator into taskflow
we can now directly use these same modules from supported
libraries instead so this moves the usage of everything except
uuidutils which wasn't moved over to using those newly published
libraries.

Part of blueprint integrate-and-use-oslo-utils-serialization

Change-Id: I1183bda96e1ddb062d9cab91990186f0f56f0a0e

Update hacking to the new requirements version and
fix about half of the new reported issues. The other
hacking issues are for now ignored until fixed by
adjusting our tox.ini file.

This commit fixes the following new hacking errors:

H405 - multi line docstring summary not separated
       with an empty line
E265 - block comment should start with '# '
F402 - import 'endpoint' from line 21 shadowed by
       loop variable

Change-Id: I6bae61591fb988cc17fa79e21cb5f1508d22781c

- Convert the various functions that take a task detail into
  ones that take atom details (since this is now the generic
  type they should take).
- Don't expose the detail type strings as part of the atom
  detail api, leave those as private hidden strings and provide
  conversion functions from string<->class instead.
- Have the logbook objects contain the following new methods
  to reduce the dependence on persistence_utils to do the same.
  - to_dict() which converts the current object into a dict
  - from_dict() which converts the provided dict into a object
  - merge() which merges a incoming objects data with the current
    objects
- Have the persistence backends + storage + action engine use these
  new methods instead of there current usage.
- Don't compare to logbook.RETRY_DETAIL or logbook.TASK_DETAIL since
  python has the isinstance function just use it (ideally we should
  fix the code so that this isn't even needed, usage of isinstance
  means something is not designed/structured right).
- In storage tests we can't assume that failures will be non-lossy
  since under certain backends when a failure is stored information
  about the internally held exc_info is lost, so take this into
  account when testing by using matches() where applicable.

Change-Id: Ie8a274cfd4cb4e64e87c355dc99d466d74a4e82c