Cleanup of topology manager to match floodlight style. Remove StackTraceUtil.

...va/net/floodlightcontroller/core/internal/Controller.java

...tcontroller/devicemanager/internal/DeviceManagerImpl.java

...ntroller/linkdiscovery/internal/LinkDiscoveryManager.java

...va/net/floodlightcontroller/topology/TopologyManager.java

...in/java/net/floodlightcontroller/util/StackTraceUtil.java

...troller/devicemanager/internal/DeviceManagerImplTest.java