highlevel 'unit'-test for refactoring of (Vpc)VirtualNetworkApplianceManagerImpl

(cherry picked from commit b8112ac79e6205573b15898f83192adf4df74626)
rats

(cherry picked from commit 7f14da6406679407d6e02e5fb2974da82f6eeaa5)
rename networkMgr to networkMdl to prevent name clashes in mocks of
VirtualRouterElement and VirtualNetworkApplianceManagerImpl
(cherry picked from commit 44be1764863b369c9bcc5c8cc7ddd05405649071)

Conflicts:
	server/src/com/cloud/network/element/VirtualRouterElement.java
	server/src/com/cloud/network/element/VpcVirtualRouterElement.java