Update secgroup API for new get/list/search API
Update secgroup API for new get/list/search API

Security group API now conforms to the new get/list/search
interface. Instead of a Nova object being returned, we now return
a dict (or list of dicts).

Change-Id: I0b84ef6065101948ffb2a0f56235bda7a071ad17

jsmartin/shade,jsmartin/shade,dtroyer/python-openstacksdk,openstack-infra/shade,openstack/python-openstacksdk,stackforge/python-openstacksdk,openstack-infra/shade,dtroyer/python-openstacksdk,stackforge/python-openstacksdk,openstack/python-openstacksdk