Do not run "ovs-ofctl add-flow" with an invalid in_port

Since ofport is a string, we have to convert it to integer to
check it expresses a negative number or not.

Also unit tests are added/corrected.

Change-Id: If85595f1b8ecb40ea41edda52706fb1bd41cb1ab
Related-Bug: 1238445
Removes unused nvp plugin config param

nvp_cluster_uuid is no longer used; it was missed
during the configuration file tweaks that was done
during Havana.

Change-Id: Id6dd684833c99453cd97d88584be04d99fd21550
Closes-bug: #1251086
Round-robin SVI switch selection fails on Cisco Nexus plugin

Fixes bug 1250969

This fix addresses improper behavior with the Cisco Nexus plugin's
selection of Nexus switch on which to place a Switch Virtual Interface
(SVI) when round-robin switch placement is enabled.

The expected behavior when round-robin SVI switch selection is configured
via the cisco_plugins.ini file, i.e.:
    [cisco]
    nexus_l3_enable = True
    svi_round_robin = True
is that when a virtual router interface is created, the Nexus plugin should
select the Nexus switch with the least number of SVI interfaces configured
for creating the new SVI. The current selection is based on the first
entry in a dictionary, and is therefore indeterminate.

Similarly, this fix also addresses incorrect behavior when round-robin
selection is disabled. In this case, the desired behavior is that
the plugin should select the first switch which appears in the Nexus
switch configuration. Instead, the current selection is also based on the
first entry in a dictionary, and is likewise indeterminate.

Change-Id: I548c1efaa8b54695246251b6823ab59e077836fe
Lower severity of log trace for DB integrity error

LOG.exception is not appropriate, since a concurrent
port creation can occur and it has been dealt with
in the except block.

This avoids spooking users who are on the hunt for
real bugs.

Supports fix for 1239637

Change-Id: I9489702ee63db0b004fe41195fa4727af261d514
Add log statements for policy check failures

Misconfiguration of the policy.json file may
cause policy check failures. It's kind to the
developer to log the underlying exception
so that he/she can have more information as to
how to address the problem.

Closes bug: #1246139

Change-Id: I8664959cb98b3a41d159db3acb91da9baba810ae
Imported Translations from Transifex

Change-Id: I38683ac890169536497e2c1ed9178d00a441328b
Merge "Imported Translations from Transifex"
Merge "Lower severity of log trace for DB integrity error"
Merge "Add log statements for policy check failures"
Imported Translations from Transifex

Change-Id: If02d797b5d423db899bba128e2efedfd4afb1ad3
Merge "Removes unused nvp plugin config param"
Merge "Round-robin SVI switch selection fails on Cisco Nexus plugin"
Merge "Do not run "ovs-ofctl add-flow" with an invalid in_port"