General link discovery module cleanup.

* Removed all events we don't use from the event system (switch and port
  events, link updates)
* Refactored event interface to two separate methods to match the other event
  interfaces
* Removed the LDUpdate class and moved all the event enums and classes to be
  internal to the LinkDiscoveryManager
* Removed all LinkTypes we no longer used and moved the one remaining type
  to the ILinkDiscoveryService. After this the ILinkDiscovery interface is
  no longer needed.
* Made Link immutable
* Removed the linkdiscovery.internal package as it only contained one class
* Readability improvements to LinkDiscoveryManager

Change-Id: Ifae97879aadc49b70a7b3d2294dcc540538c2cfc
diff --git a/src/main/resources/META-INF/services/net.floodlightcontroller.core.module.IFloodlightModule b/src/main/resources/META-INF/services/net.floodlightcontroller.core.module.IFloodlightModule
index 5e6c88a..37be163 100644
--- a/src/main/resources/META-INF/services/net.floodlightcontroller.core.module.IFloodlightModule
+++ b/src/main/resources/META-INF/services/net.floodlightcontroller.core.module.IFloodlightModule
@@ -1,6 +1,6 @@
 net.floodlightcontroller.core.FloodlightProvider
 net.onrc.onos.core.topology.TopologyPublisher
-net.onrc.onos.core.linkdiscovery.internal.LinkDiscoveryManager
+net.onrc.onos.core.linkdiscovery.LinkDiscoveryManager
 net.floodlightcontroller.restserver.RestApiServer
 net.floodlightcontroller.threadpool.ThreadPool
 net.floodlightcontroller.core.test.MockFloodlightProvider