Add run_cross_tests.sh script

Script `run_cross_tests.sh` can be used for running unit tests in
other projects using the current package's code.

Change-Id: Iad636216cd73d2eeb70448fda789c0ad9d579b3a
Related-Bug: #1367354
Add description for test_models_sync function

Add description of the diff list that is generated in
test_modes_sync function for readability reason.

Change-Id: I3ecaf2da5a22b1835e0c6604b59f9cd1874747de
Fixup Fixtures Use in db test classes.

With Fixture objects and test cases it is important to upcall first
rather than later to allow base classes to configure their internal
test tracking state. Failing to do so allows bugs like this one to
occur - when failure occurs early, the state required to gather
environmental details about the failure is not prepared, and the
test machinery will raise secondary exceptions as it tries to do that.
This may even obscure the original error.

I've taken a fairly minimal approach here - I think it would be
possible and likely even desirable to get rid of the test classes
altogether - this module appears to have very little, if any, actual
test code - its all glue for managing the test database connections.
However I know zzzeek is working on a fairly large reorg in this
area and I don't want to conceptually clash with that - we can do
further cleanups later.

Co-Authored-By: Robert Collins <rbtcollins@hp.com>

Change-Id: Ic9f24aa2352d097a10be8420b701fa9f588b21b0
Closes-Bug: #1330763
Use __qualname__ if we can

Due to pep-3155 functions and methods will now have more
uniform qualified names that we can and should use when
we can (mainly applicable to python 3.x).

Once https://review.openstack.org/#/c/122495/ goes in we
can just use that module instead to get similar functionality.

Change-Id: Iea9e74aca38aa79c9294fd6e786551e91143900c
Merge "Fixup Fixtures Use in db test classes."
Merge "Use __qualname__ if we can"
Merge "Add description for test_models_sync function"
Merge "Add run_cross_tests.sh script"
Update help string to use database

Use "database" instead of "db" in help string as noticed during
review of https://review.openstack.org/#/c/120200/

Change-Id: I6e17c759ae101af23b7d57c13dfba26aa6feddb6
Updated from global requirements

Change-Id: I7e4d84dc6c45c1220766261363f2fabc5085fe31
Merge "Update help string to use database"
Imported Translations from Transifex

Change-Id: I293172684fcff520ae445836bb132bf1a919d127