Move NullFilter to new package structure

Author: cboehme

src/main/java/org/culturegraph/mf/stream/pipe/NullFilter.java renamed to src/main/java/org/culturegraph/mf/mangling/NullFilter.java

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.culturegraph.mf.stream.pipe;
+package org.culturegraph.mf.mangling;
 
 import org.culturegraph.mf.framework.StreamReceiver;
 import org.culturegraph.mf.framework.annotations.Description;

src/test/java/org/culturegraph/mf/stream/pipe/NullFilterTest.java renamed to src/test/java/org/culturegraph/mf/mangling/NullFilterTest.java

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.culturegraph.mf.stream.pipe;
+package org.culturegraph.mf.mangling;
 
 import static org.mockito.Mockito.inOrder;
 import static org.mockito.Mockito.verifyNoMoreInteractions;