Misc improvements. Primarily Javadoc.

Change-Id: I083bbf559d53fa25f79d4e1e53eb15c6b96290f2
diff --git a/core/api/src/main/java/org/onosproject/store/service/LogicalClockService.java b/core/api/src/main/java/org/onosproject/store/service/LogicalClockService.java
index 0114b02..7592b12 100644
--- a/core/api/src/main/java/org/onosproject/store/service/LogicalClockService.java
+++ b/core/api/src/main/java/org/onosproject/store/service/LogicalClockService.java
@@ -20,7 +20,7 @@
 /**
  * Service that issues logical timestamps.
  * <p>
- * The logical timestamps are useful for establishing a total ordering of
+ * Logical timestamps are useful for establishing a total ordering of
  * arbitrary cluster wide events without relying on a fully synchronized
  * system clock (wall clock)
  */