LBaaS: fix reported binary name of a loadbalancer agent

Loadbalancer agent's actual binary name differs from what it reports
to Neutron server, so need to fix:
neutron-loadbalancer-agent -> neutron-lbaas-agent

Closes-Bug: #1248222
Change-Id: Ic4e05d0258ba8eb48b96c60d69c1dbf9f27731f6
Replace mox in unit tests with mock

blueprint remove-mox

Removing mox from test-requirements.txt will be done in another patch
because stubout module is a part of mox and it is used in several modules.

Change-Id: I9370e8da815d2234a032a8875da73a86d4126d46
Reduce the severity of dhcp related log traces

Due to timing issues, when the agent synchronizes
with the server wrt the representation of server's
and agent's networks, networks may have already
been deleted from the db. In such circumstances,
it is more appropriate to emit warnings rather than
full-blown exceptions as the agent handles these
circumstances just fine.

Close-bug: 1251874

Change-Id: I4b118b6087c7f42226f0d4265d2176c028d99f22
Merge "Replace mox in unit tests with mock"
Merge "Reduce the severity of dhcp related log traces"