Include ConsistentMap name in Timeout exception message

Change-Id: Ibfdd898f98b59862f2ed0e7d201ed265c1dcd592

@@ -225,7 +225,7 @@ public class DefaultConsistentMap<K, V> extends Synchronous<AsyncConsistentMap<K
             Thread.currentThread().interrupt();
             throw new ConsistentMapException.Interrupted();
         } catch (TimeoutException e) {
-            throw new ConsistentMapException.Timeout();
+            throw new ConsistentMapException.Timeout(name());
         } catch (ExecutionException e) {
             Throwables.propagateIfPossible(e.getCause());
             throw new ConsistentMapException(e.getCause());

@@ -36,6 +36,13 @@ public class ConsistentMapException extends StorageException {
      * ConsistentMap operation timeout.
      */
     public static class Timeout extends ConsistentMapException {
+        public Timeout() {
+            super();
+        }
+
+        public Timeout(String message) {
+            super(message);
+        }
     }
 
     /**