DeviceManager and entity classification updates/fixes

If we cannot find an entity in the primary index we need to
classify it into an IEntityClass and the search in the class index.

* Fixed couple of bugs in Device.getIPv4Addresses().
* Add more debugging output to DeviceManagerImpl

updated CLI (https://github.com/floodlight/floodlight/pull/199)

* implement findDestDeviveByEntity()
* findDevice() and findDestDevice() will now throw an exception of the
  supplied fields are not sufficient for the lookup
* test and comment polishing
* reorganizing testing code

[BSC-1838]

Make getLinkType() in LinkDiscoveryManager public. (https://github.com/floodlight/floodlight/pull/198)

Re-add getLinkType() into LinkDiscoveryManager. (https://github.com/floodlight/floodlight/pull/197)

making it possible to get LinkType information both from LinkInfo.getLin... (https://github.com/floodlight/floodlight/pull/196)

The Web UI now has icons and stuff (https://github.com/floodlight/floodlight/pull/195)

(These icons were designed from scratch by me with ASL 2.0 license.)
Nodes are now labeled with their name (DPID or IP+MAC).
Added a hack to ignore multiple attachment points for hosts, since
Floodlight's concept of attachment points doesn't correspond to the
physical topology.

Fix a NPE in injectOFMessage

Added less confusing constructor for OFActionOutput (https://github.com/floodlight/floodlight/pull/193)

and associated javadocs

[BSC-1838]

* IEntityClassifier only returns a single entity class per entity and all
  entities of a device must belong to the same entity class. Semantics for
  multiple classes was unclear.

* IEntityClassifier is now an IFloodlightService to have a cleaner way of
  setting the classifier to use (the classifier needs to be set before
  DeviceManager.startUp() is called).

[BSC-1838]

	Fix an issue with static flow entry pusher where it was not correctly (https://github.com/floodlight/floodlight/pull/192)

Don't set role again if it's the same. Partial fix for BSC-1835 (https://github.com/floodlight/floodlight/pull/190)

Fix a topo issue and comment updates. (https://github.com/floodlight/floodlight/pull/191)

2 - Fix some tabbing.

Make role change code more robust. (https://github.com/floodlight/floodlight/pull/189)

Update to getRoute() method to provide complete path even when only one switch is involved. (https://github.com/floodlight/floodlight/pull/188)

getRoute() method must provide the complete route from source port to destination port even when the route involves only one switch.  getRoute() must also not provide route from same switch-port to itself.

Refactoring of Route class. (https://github.com/floodlight/floodlight/pull/187)