Update License Headers to replace Nicira with VMware

In the process __init__.py involved have been emptied;
vim modelines and author lines have been dropped from
the license headers affected by the change as well.

Partial-implements blueprint nicira-plugin-renaming

Change-Id: I9c535b59bb2e83f275816472e0e32b41444d3bbe

neutron/db/__init__.py

@@ -1,17 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# Copyright 2011 Nicira Networks, Inc.
-# All Rights Reserved.
-#
-#    Licensed under the Apache License, Version 2.0 (the "License"); you may
-#    not use this file except in compliance with the License. You may obtain
-#    a copy of the License at
-#
-#         http://www.apache.org/licenses/LICENSE-2.0
-#
-#    Unless required by applicable law or agreed to in writing, software
-#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-#    License for the specific language governing permissions and limitations
-#    under the License.
-# @author: Somik Behera, Nicira Networks, Inc.
-# @author: Brad Hall, Nicira Networks, Inc.