Convert multiple-create v3 plugin to v2.1

Changes required to have the multiple create v3 plugin natively
support the v2.1 API. The following Server creation parameters
are reverted:

os-multiple-create:min_count -> min_count
os-multiple-create:max_count -> max_count
os-multiple-create:return_reservation_id -> return_reservation_id

Removes min_count parameter for a test which should never have
been included but due to a gap in input validation was ignored.

Partially implements blueprint v2-on-v3-api

Change-Id: Ie435c357958066e9fde40eab54826261ee9d4226
Convert migrate_server v3 plugin to v2.1

Changes required to have v3 plugin natively support
the v2 API.

The migrate_live action is reverted back to os-migrateLive

Partially implements blueprint v2-on-v3-api

Change-Id: Ib3332ecfbf47ed6cad6108399083f0c26b7eebfe
Port v2 images extension to work in v2.1(v3) framework

Ports v2 images extension and adapts it to the v2.1/v3 API
framework. API behaviour is identical with the exception
that there is no support for XML. Also

- unittest code modified to share testing with both v2/v2.1
  where appropriate
- Adds expected error decorators for API methods

Partially implements blueprint v2-on-v3-api

Change-Id: I7b15a56f41612e3bbf5d59c3ad44fd32386ff315
Convert v3 servers return_reservation_id behaviour to v2.1

Changes return reservation id format on server create to
the v2.1 format.

Adds api sample tests for the os-multiple-create plugin

Partially implements blueprint v2-on-v3-api

Change-Id: I148cce80fb4b19a4240e00ca206fcb7bac20f357
Convert v3 hypervisor plugin to v2.1

This patch convert v3 hypervisor plugin to v2.1 and makes v2
unit tests share between v2 and v2.1.

Unit tests has been modified in optimized way.

The differences between v2 and v3 are described on the wiki page
https://wiki.openstack.org/wiki/NovaAPIv2tov3.

Partially implements blueprint v2-on-v3-api

Change-Id: I23ffc10d4c0170cb43ef8aeebf69ae2794a08827
Merge "Convert migrate_server v3 plugin to v2.1"
Merge "Convert v3 hypervisor plugin to v2.1"
Merge "Convert multiple-create v3 plugin to v2.1"
Merge "Convert v3 servers return_reservation_id behaviour to v2.1"
Merge "Port v2 images extension to work in v2.1(v3) framework"