Use valid IP addresses values in tests

Currently we use strings like 'fake_address', 'localhost', etc
as IP addresses values in DP API tests. This works great when
running tests on SQLite or MySQL backends, where IP addresses
are stored as plain strings. But in PostgreSQL there is a special
column type (INET), which checks inserted values to be valid IP
addresses, so tests fail.

This patch ensures we use valid IP addresses values instead of
arbitrary strings in DB API tests.

Blueprint: db-api-tests-on-all-backends

Change-Id: I2026bab612fcac09b245f6745810b6200f1f2443
Fix HTTP response for PortNotFound during boot

If a non-existent Quantum port is passed as a network parameter during create
instance, Nova API should return an HTTP BadRequest.

Fixes bug #1195468

Change-Id: I5914fda076fdd3ff20c81984364ca725edae1a78
Merge "Fix HTTP response for PortNotFound during boot"
Merge "Use valid IP addresses values in tests"