The new apiclient.exceptions hierarchy is more comprehensive
and it covers almost all HTTP error status codes. These
exceptions can be used in novaclient, keystoneclient,
glanceclient, and other client projects thus providing a
single inteface.
Users can have benefit from OpenStack clients raising exceptions
of known classes while now every client has its own classes making
difficult to catch, e.g., NotFound for every client.
Change-Id: Ia7b25880e0ffca3526525a0f0e77c7e77c4f0076
fba0cd51d9