This patch rehomes a bulk of neutron.api.v2.attributes into lib
with the following notable aspects:
- A new AttributeInfo class is available and wraps a resource's
attribute dict to provide operations with the attributes. The
class can be used as a operational wrapper on a dict of attrs, or
it an be used as a transport of attrs based on the consumer's need.
- A global singleton attribute map RESOURCES is available and
is initially populated with core resources.
- Some unit tests are beefed a little and make them more modular.
- Some huge comments into the devref.
- The fixture for API defs is updated to support backing up the
global RESOURCES dict.
Change-Id: Ic455e1af2796e58025381160dc5c3b83217413fa
e4016525ad