Add Javadoc for hashCode and equals methods of Contact

src/main/java/envoy/data/Contact.java

@@ -62,13 +62,19 @@ public abstract class Contact implements Serializable {
 	public String toString() { return String.format("Contact[id=%d,name=%s, contacts=%s]", id, name, contacts); }
 
 	/**
-	 * {@inheritDoc}
+	 * Provides a hash code based on the ID of this contact.
+	 * 
+	 * @since Envoy Common v0.1-beta
 	 */
 	@Override
 	public int hashCode() { return Objects.hash(id); }
 
 	/**
-	 * {@inheritDoc}
+	 * Tests equality to another object. If that object is a contact as well,
+	 * equality is determined by the ID.
+	 * 
+	 * @param obj the object to test for equality to this contact
+	 * @return {code true} if both objects are contacts and have identical IDs
 	 */
 	@Override
 	public boolean equals(Object obj) {