Correctly inherit __table_args__ from parent class

Where unique constraints are added to certain tables by populating
__table_args__, we need to ensure we inherit the top level
__table_args__ that define the default storage engine to use when
creating tables.

Change-Id: Ib886b84922830b60282b4f882591e43f5041e713
Fixes: bug 1288358
OFA agent: use hexadecimal IP address in tunnel port name

The remote IP address is used to form the tunnel port name
With some OVS/Linux combinations there is a 15 character limit
on port names, so a name like 'gre-192.168.10.10' does not work.
This fix uses the shorter hexadecimal representation of
the IP address instead.
This problem was reported and fixed for OVS agent.

Closes-Bug: 1294474

Change-Id: Ieab1eb8a5c430f69aff61a317cc28f23ba95ad2d
set api.extensions logging to ERROR in unit tests

neutron.api.extensions generates a lot of output in a normal
unit test run. It's responsible for > 80% of the lines in the
subunit_log.txt. Logging each file load 10k times slows everything
down, takes up valuable memory, and doesn't really help with testing.

Instead we can set this to ERROR level in a fixture to ignore most
of that logging and help make the unit tests run faster.

Change-Id: I86b41f20342b4080859ee036220ddffa200f0562
Merge "set api.extensions logging to ERROR in unit tests"
Merge "Correctly inherit __table_args__ from parent class"
Merge "OFA agent: use hexadecimal IP address in tunnel port name"