Fix requirements file ordering

We have been enforcing alphabetical ordering in requirements file.
See https://review.openstack.org/#/c/66090/
These wrong ordering will cause problems with the change to enforce
that ordering.

Change-Id: Iaddd33aba22a2cf58b2a2fa69d64925848f6e1d7
Enforce alphabetical ordering in requirements file

Change-Id: Iaaa52acaa6005d9fbcd17b23523f61cea16e5a30
Make TRADITIONAL the default SQL mode

Rather than log a warning when TRADITIONAL mode is not enabled,
just make it the default. If this causes INSERTs or UPDATEs from
applications to break, it just exposes that they are inserting
broken data to begin with.

Change-Id: I84c1781454ed5f46c7a135c96bafc575f313f9bc
db: move all options into database group

This moves all the options in the database group so it's easier to iterate
over them once and for all in order to pass them to the method creating
the engine.

Change-Id: If3117f01d746f12a07cf4c3b4c4fc1a1ce8b679d
Merge "Fix requirements file ordering"
Merge "Enforce alphabetical ordering in requirements file"
notify calling process we are ready to serve

Systemd notification should be sent in-process, otherwise systemd might
miss the subprocess sending notification.
See systemd bug https://bugzilla.redhat.com/show_bug.cgi?id=820448

Taken from keystone project commit
abc06716d027d68f0da3b0f559fa7c85a21804d5

Improvements from Keystone version:

    * add unset_environment parameter
    New parameter unset_environment was added to sd_notify
    http://www.freedesktop.org/software/systemd/man/sd_notify.html
    to ensure service readiness is sent only once.

    * add onready() method to simulate systemd environment
    For testing purposes and optional use with SysV initscripts.

    * unit test added

    * docstrings for notification methods

Patch includes deployment in openstack.common.service.
It does not have an effect when running the service outside
the systemd environment.

Implements: blueprint service-readiness
Change-Id: I80f325c9be9c171c2dc8d5526570bf64f0f87c78
Revert "Removed set_loaded() method from Resource class"

This patch broke python-novaclient.
It turns out novaclient uses get() to support lazy loading details.
Add a docstring to get() to clarify its usage.

see novaclient/tests/v3/test_servers.py#L54
This reverts commit 0c4d2c76a6876dd8873cca2736ca5a7f3da66c69.

Change-Id: I0a2936b00de3ca17f0e40e3d5226ecdaf1329295
Merge "Make TRADITIONAL the default SQL mode"