Cleaning up Javadocs in core-ui classes.
Added common constants to AbstractCellFormatter.

Change-Id: Ie20ea62f059646e7d6c7f3660dd60a60c40532fe
diff --git a/core/api/src/main/java/org/onosproject/ui/model/topo/UiRegionLink.java b/core/api/src/main/java/org/onosproject/ui/model/topo/UiRegionLink.java
index 45a27b9..afc6777 100644
--- a/core/api/src/main/java/org/onosproject/ui/model/topo/UiRegionLink.java
+++ b/core/api/src/main/java/org/onosproject/ui/model/topo/UiRegionLink.java
@@ -36,7 +36,7 @@
      * link identifier is one that has region IDs as source and destination.
      *
      * @param topology parent topology
-     * @param id       canonicalized link identifier
+     * @param id       canonicalized link ID
      * @throws IllegalArgumentException if the link ID is not region-region
      */
     public UiRegionLink(UiTopology topology, UiLinkId id) {