Cleanup log marker in neutronv2 api

Cleanup log according to docs.openstack.org/developer/oslo.i18n/guidelines.html
Add LI marker for LOG.info.
Correct debug log information in _get_instance_nw_info function.
and other log cleanup.

Change-Id: Ic7fba3e750196dfb3296291cd4d4d21bc06d47c6
Metadata: use instance objects instead of dictionary

Commit 8ad28f924c7ff4c932bd280032cf7c8ffe5aa20a added object
support to the metadata service. We can now use an instance
object format instead of dictionary.

Change-Id: Ibe6a1e68019ad59cb57c2e406ca38fdabb8eedec
Call controller methods directly in test_evacuate

In API unit testing, making call through WSGI is little bit overhead,
wherever applicable, unit tests can make direct call to controller
methods.

Some unit tests needs WSGI call to tests more than one plugin together.

This patch makes above cleanup in test_evacuate.

Partially implements blueprint v2-on-v3-api

Change-Id: Ia664a9c71d7d62f39a2dbed7605d102526f4520c
Merge "Cleanup log marker in neutronv2 api"
Merge "Call controller methods directly in test_evacuate"
Merge "Metadata: use instance objects instead of dictionary"