Change description of default security group

The description for default security group in neutron
is “default”.
This confuses the end users, so updated the description
from “default” to “Default security group”.
Closes-Bug: #1291570

Change-Id: I9e024de935e8d17afd3d459cfa17e9feb0cd79fa
Don't block on rpc calls in unit tests

While running unit tests I noticed that all of the test cases from
TestOvsNeutronAgent were taking just over 15 seconds.  This is because
it was waiting for the rpc call response timeout.  Since the tests
weren't actually failing, it's clear the code doesn't actually care
about the response anyway, so just set the messaging config to not
wait for the response.

On my dev box, this dropped test runtime for this file from 1024
seconds to 3 seconds, which is an obvious *HUGE* improvement.

Someone pointed out that an earlier change
(086496bfc45e01cd2905a074d526a7d513bf4ec2) intended to make calls
return immediately for *all* tests, but removing use of RpcProxy
caused this to stop working.

Change-Id: Id07c1d1727a3f4087f0a97681388fb5d69740f8d
Merge "Change description of default security group"
Merge "Don't block on rpc calls in unit tests"