This is to avoid service module dependency on importutils that are now
moved to oslo.utils.
The following changes are included:
* neutron/openstack/common/eventlet_backdoor.py
5d40e14 Remove code that moved to oslo.i18n
90ae24b Remove redundant default=None for config options
fcf517d Update oslo log messages with translation domains
* neutron/openstack/common/loopingcall.py
5d40e14 Remove code that moved to oslo.i18n
e377393 Changes calcuation of variable delay
ab5d5f1 Use timestamp in loopingcall
bc48099 Log the function name of looping call
fb4e863 Remove deprecated LoopingCall
fcf517d Update oslo log messages with translation domains
* neutron/openstack/common/service.py
5d40e14 Remove code that moved to oslo.i18n
6ede600 rpc, notifier: remove deprecated modules
* neutron/openstack/common/systemd.py
17c4e21 Fix docstring indentation in systemd
* neutron/openstack/common/threadgroup.py
5a1a016 Make stop_timers() method public
fdc8883 Add graceful stop function to ThreadGroup.stop
2d06d6c Simple typo correction
4d18b57 threadgroup: use threading rather than greenthread
Change-Id: I4887545f861a93223e2c7cbcdd39efe991bff547