Improve test coverage for quantum wsgi module

OpenStack quantum.wsgi package includes a lot of classes not covered
with unit tests. This change adds such unit tests.

Fixes: bug #1136027
Change-Id: I16dd35389bf82f2818b74d1fb4cf7f7a6bebce28
Allow tests in TestDhcpAgentEventHandler run independently

Tests in TestDhcpAgentEventHandler depend on dhcp_confs
option that is defined in quantum.agent.linux.dhcp. We have
to register the option in order to allow independent testing.

This problem is similar to bug #1125951.

Fixes: bug #1156696

Change-Id: I323908c6f70697e056294b1817ff32ce5d32b32c
Validate protocol when creating VIP.

Fixes: bug #1123114

When creating a VIP, check that the protocol matches the protocol
for the associated pool. If not, raise an exception.

Change-Id: Iba318eda935ccc89dbe8244e00f36ebdfcce65e0
Merge "Improve test coverage for quantum wsgi module"
Merge "Validate protocol when creating VIP."