ONOS-4971: Synthetic Link Data -- WIP, merge anyway

- created temp Topology2 View (topoX) to "process" and display topology data.
- made root layout parent of itself (just like /.. = /) to simplify layout hierarchy operations.
- added nodeType property to JSON rep of regions/devices/hosts.
- augmented peers to include devices.
- added skeleton topo2NavRegion event.

Change-Id: I8219125d7dfe33d211350ae27111a3d9de6eb4ca
diff --git a/core/api/src/main/java/org/onosproject/ui/UiTopoLayoutService.java b/core/api/src/main/java/org/onosproject/ui/UiTopoLayoutService.java
index 287cc43..0036521 100644
--- a/core/api/src/main/java/org/onosproject/ui/UiTopoLayoutService.java
+++ b/core/api/src/main/java/org/onosproject/ui/UiTopoLayoutService.java
@@ -63,7 +63,7 @@
      * @param layoutId layout identifier
      * @return set of peer layouts; empty set if layout has no peers
      */
-    Set<UiTopoLayout> getPeers(UiTopoLayoutId layoutId);
+    Set<UiTopoLayout> getPeerLayouts(UiTopoLayoutId layoutId);
 
     /**
      * Returns the set of the child layouts of the specified layout.