Fix re-creation of the pool directory

Whenever vip is deleted the complete pool directory
is deleted, but since pool is still alive the get_stats
function recreates the directory. The fix prevents the
re-creation of the directory. Respective unit test case
is also modified

Change-Id: I577e8e3a51db361210aa83a6c7f9b4f61210e924
Closes-Bug: #1317871
changes ovs agent to get bridges via ovs_lib

ip_lib is currently used to list the bridges
in the Open vSwitch neutron agent.

use of ip_lib blocks reuse of the Open vSwitch agent
with userspace only open vSwitchs implementations.

this patch replaces calls to ip_lib with ovs_lib.get_bridges

Closes-Bug: #1331569
Change-Id: I5935d39b314055063a64266bda0cc4c2d1ac05fc
Imported Translations from Transifex

Change-Id: I5bcbd94a8df99b5fe3125e1dee45cfceeeb29ac6
Merge "Fix re-creation of the pool directory"
Replace occurences of 'test_tenant' with 'test-tenant' in tests

tenant_id will now be consistent among all resources created.
This is important when getting or listing resources by tenant_id.
Most resources are created under the 'test-tenant', while
metering and security groups were created under 'test_tenant'.

Closes-Bug: #1335821
Change-Id: Ifde22814ab5c302e751f2102f6fd7ef52c932126
Switch to using of oslo.db

oslo.db first stable release has been cut and we can start using it
instead of openstack/common/db/* code which is now marked obsolete.

Change-Id: I1ccf896922a5a762d37a1a3b93c56c8b8ae8c085
Merge "changes ovs agent to get bridges via ovs_lib"
Merge "Switch to using of oslo.db"
Merge "Imported Translations from Transifex"
Merge "Replace occurences of 'test_tenant' with 'test-tenant' in tests"