fix javadoc warnings

Author: rashtao

src/main/java/com/arangodb/velocypack/VPackParser.java

@@ -166,7 +166,7 @@ private VPackParser(final Map<Class<?>, VPackJsonSerializer<?>> serializers,
 	 * @param attribute
 	 * @param type
 	 * @param deserializer
-	 * @return
+	 * @return this
 	 */
 	@Deprecated
 	public VPackParser registerDeserializer(
@@ -186,7 +186,7 @@ public VPackParser registerDeserializer(
 	 * @deprecated use {@link VPackParser.Builder#registerDeserializer(ValueType, VPackJsonDeserializer)} instead
 	 * @param type
 	 * @param deserializer
-	 * @return
+	 * @return this
 	 */
 	@Deprecated
 	public VPackParser registerDeserializer(final ValueType type, final VPackJsonDeserializer deserializer) {
@@ -199,7 +199,7 @@ public VPackParser registerDeserializer(final ValueType type, final VPackJsonDes
 	 * @param attribute
 	 * @param type
 	 * @param serializer
-	 * @return
+	 * @return this
 	 */
 	@Deprecated
 	public <T> VPackParser registerSerializer(
@@ -219,7 +219,7 @@ public <T> VPackParser registerSerializer(
 	 * @deprecated use {@link VPackParser.Builder#registerSerializer(Class, VPackJsonSerializer)} instead
 	 * @param type
 	 * @param serializer
-	 * @return
+	 * @return this
 	 */
 	@Deprecated
 	public <T> VPackParser registerSerializer(final Class<T> type, final VPackJsonSerializer<T> serializer) {

src/main/java/com/arangodb/velocypack/VPackStringSlice.java

@@ -10,7 +10,7 @@
 public class VPackStringSlice implements Comparable<VPackStringSlice> {
     private byte[] vpack;
     /**
-     * Index of the string bytes within {@link vpack},
+     * Index of the string bytes within {@link this#vpack},
      * i.e. tag byte and length are somewhere before this index.
      */
     private int start;