Deprecate log_format and change default to None

Commit 3e71cc4c8c7e08784f44c2e337a585e562b93ec5 fixed an issue with
ignoring log_format, but changed the default logging formatter.  This
led to being unable to use the former context aware formatter without
configuring log_format='' explicitly.

This change sets log_format to None so that the default is a context
aware formatter, but setting log_format works as intended.

Additionally, since log_format is mutually exclusive with some of the
other config formatting options, such as logging_default_format_string,
it should be deprecated.

Bug 1167388

Change-Id: I281ed7fe3448403f27a4cd318fc21915027906cc
Improve python3 compatibility

Change print statements so that it works with python3
as well.

Change-Id: Iff16b62e4b875c79862c9af7726ea77627aa7b4f
Signed-off-by: Chuck Short <chuck.short@canonical.com>
Add test coverage for sqlite regexp function

Add some tests which for the regexp function which we install for
sqlite.

Need test coverage to catch e.g. a regression of the fix for
bug #1031846.

Change-Id: I4bd77d0d93c4fc85588e6e6d5a559e68133dbf73
Update processutils.

This is another example of something which was imported from nova
but where nova was never moved across to use the oslo version. The
code has since diverged. This review syncs up the two versions,
and will be followed by a nova review to move nova across to the
oslo implementation.

Unit test coverage for this new version is 83%. I want to improve
that, but I'll do it in a later review.

I will also need to update cinder, quantum and nova to this new
version of the code once this merges. I will do moniker as well
because I am a nice guy.

Change-Id: Ie0731c56c9aab547b5d5b905bf4ed8eff3eae3bd
Merge "Update processutils."
Merge "Deprecate log_format and change default to None"
Merge "Add test coverage for sqlite regexp function"