NSX policy is conceptually a separate endpoint, with a different
set of managed objects, but same connection management funtionality.
NsxLib user might want to have two instances of the library (based
on different configurations), one for policy and one for core nsx api.
Note: This patch will require adjustments in vmware_nsx UTs, due to
resource mocks.
Change-Id: I0d3660a8f9092bcf4e2fb4bf93e86c0dc7be7aaa