Add unit tests covering single operations to ODL

This commit adds the remaining test cases (create and update
operations) to fully cover sync_single_resource. It also defines the
filter_* methods as static or class methods and removes their duplicate
arguments.

Change-Id: I6b6153ea577bd685576690559b1c389490ee525d
Closes-Bug: #1325184
Eliminate OrderedDict from test_api_v2.py

Neutron cannot possibly be passing tests under Python 2.6, as
neutron/tests/unit/test_api_v2.py is referencing
collections.OrderedDict, which does not exist in Python 2.6.
Since there is no reason to use an OrderedDict in this case,
this replaces it with a simple dict.

Change-Id: I1b9886f508c4c8b96cf50c50f157c1960da433fc
Closes-Bug: #1372571
Merge "Eliminate OrderedDict from test_api_v2.py"
Merge "Add unit tests covering single operations to ODL"