Adding to the 'devices' cli command an output that displays the local connectivity of a device.
For example, "id=of:0000000000000203, available=true, local-status=connected 18m7s ago, role=STANDBY, ..."
Also increasing the resolution of the TimeAgo utility.

Change-Id: Ie1b89bd193552e0edd38a9ca28c5ce99b1d27c19
diff --git a/utils/misc/src/main/java/org/onlab/util/Tools.java b/utils/misc/src/main/java/org/onlab/util/Tools.java
index 6df74b0..cc769c4 100644
--- a/utils/misc/src/main/java/org/onlab/util/Tools.java
+++ b/utils/misc/src/main/java/org/onlab/util/Tools.java
@@ -541,11 +541,11 @@
         long hoursSince = (long) (deltaMillis / (1000.0 * 60 * 60));
         long daysSince = (long) (deltaMillis / (1000.0 * 60 * 60 * 24));
         if (daysSince > 0) {
-            return String.format("%dd ago", daysSince);
+            return String.format("%dd%dh ago", daysSince, hoursSince - daysSince * 24);
         } else if (hoursSince > 0) {
-            return String.format("%dh ago", hoursSince);
+            return String.format("%dh%dm ago", hoursSince, minsSince - hoursSince * 60);
         } else if (minsSince > 0) {
-            return String.format("%dm ago", minsSince);
+            return String.format("%dm%ds ago", minsSince, secondsSince - minsSince * 60);
         } else if (secondsSince > 0) {
             return String.format("%ds ago", secondsSince);
         } else {