Added missing core_plugins symbolic names

Some plugins miss short symbolic name in setup.cfg, specifically Nuage
and Metaplugin.

Conflicts:
	setup.cfg

Change-Id: I0198ae98654bbdddf8f2ba8dd3b80d0d447d6341
Closes-Bug: 1324487
(cherry picked from commit 664bdcdc7d714bcdfe503db8f59c6a3f97668df2)
Big Switch: Remove unnecessary initialization code

Removes a server_timeout parameter that was never set by anything
in the Big Switch plugin and the ML2 driver.

Also eliminates an __init__ method that didn't do anything except
incorrectly log an unset server pool warning before the inheriting
class setup the server pool.

Closes-Bug: #1331249
Change-Id: I77dd22295305b96d4702f1ea0e319dc5f82c71a8
(cherry picked from commit 24a19bfd362996cd9833a167d6eb86fdcf743b75)
Merge "Added missing core_plugins symbolic names" into stable/icehouse
Merge branch 'stable/icehouse' of https://github.com/openstack/quantum into stable/icehouse