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
Updated from global requirements

Change-Id: I576919f28d7dd1a04ce1a3795bbf940b82d0d76f
Hide ipv6 subnet API attributes

The attributes for ra mode and address mode should be hidden
until the IPv6 feature is fully implemented.

The changes in this patch will be reverted by another patch
which closes this bug.

Change-Id: I69a1a571b5beb566641200e60b84f0716c1ec138
Related-Bug: 1304093
NSX: ensure dhcp port is setup on metadata network

Change in scheduling behavior caused a regression
where the dhcp port is no longer provisioned on
the (admin) metadata network created when a subnet
is uplinked to a router.

This change recovers the past behavior and extend UT
coverage to avoid further regression.

Closes-bug: #1304127

Change-Id: I8420203f68a43368f3784adb0c4cbbe55f048662
Merge "Updated from global requirements"
Merge "NSX: ensure dhcp port is setup on metadata network"
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"
Merge "Hide ipv6 subnet API attributes"