Stop exception log in Big Switch unit tests

Reduce unit test log sizes by removing stack trace
exception logging in Big Switch unit tests.

Closes-Bug: #1370898
Change-Id: Id808edb5db567db31b6c1366e20948683f20118a
NSX: Fix foreign key constraint delete provider network

The cascade delete on the tz_network_bindings table is not
taking effect with the NSX plugin. In order to fix this, this
will require a db migration. This patch allows us to provide a
fix for this by deleting the tz_network_bindings within a transaction
to avoid the foreign key constraint. This patch fixes it this way so
that it can be backported to icehouse. Later a patch will be pushed with a
migration which corrects the db schema.

Closes-bug: #1367032

Change-Id: I19d389acc710224baff79ad114fab756b2e21cfc
Update i18n translation for VMware NSX plugin log msg's

All the existing LOG.info, LOG.warning, LOG.error and LOG.critical
messages should have _LI, _LW, _LE and _LC respectively. Also, debug
level log shouldn't be translated. This patch set will cover the vmware
directory under neutron/plugins.

Change-Id: Iba83af988cb2de919b05108f145efb19e9192ae4
Partial-Bug: #1320867
Update i18n translation for Mellanox plugin and agent log msg's

All the existing LOG.info, LOG.warning, LOG.error and LOG.critical
messages should have _LI, _LW, _LE and _LC respectively. Also, debug
level log shouldn't be translated. This patch set will cover the mlnx
directory under neutron/plugins.

Change-Id: Idfdb38360888002b066c8ac2d177a92b2ac173f4
Partial-Bug: #1320867
Merge "Update i18n translation for VMware NSX plugin log msg's"
Merge "Update i18n translation for Mellanox plugin and agent log msg's"
Merge "NSX: Fix foreign key constraint delete provider network"
Merge "Stop exception log in Big Switch unit tests"