Topology manager - removing links with after removing termination point.

Topology manager - removing links with after removing termination point.

If termination point or whole node is removed then also all corresponding
links are removed from topology.

Fix of corresponding tests.
Splitting original testing class (FlowCapableTopologyExporterTest) to
- FlowCapableTopologyExporterTest
- NodeChangeListenerImplTest
- TerminationPointChangeListenerImplTest
- TestUtils.java - contains common testing methods

DataChangeListenerBase - is common ancestor for NodeChangeListenerImplTest and
TerminationPointChangeListenerImplTest

Change-Id: I051de4e5d54d50134b14f1399db9c44123990384
Signed-off-by: Jozef Gloncak <jgloncak@cisco.com>