Move 'Translator' classes to .client.j2se subpackage in order to allow a Java 9 module for javase

javase/src/main/java/com/google/zxing/client/j2se/HtmlAssetTranslator.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.google.zxing;
+package com.google.zxing.client.j2se;
 
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;

javase/src/main/java/com/google/zxing/client/j2se/StringsResourceTranslator.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.google.zxing;
+package com.google.zxing.client.j2se;
 
 import java.io.BufferedReader;
 import java.io.IOException;

pom.xml

@@ -514,6 +514,9 @@
               </goals>
             </execution>
           </executions>
+          <configuration>
+            <ignoredDifferencesFile>${project.parent.basedir}/src/clirr/ignored-differences.xml</ignoredDifferencesFile>
+          </configuration>
         </plugin>
         <plugin>
           <groupId>org.jacoco</groupId>

src/clirr/ignored-differences.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ Copyright (C) 2019 ZXing authors
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ -->
+<differences>
+  <difference>
+    <className>com/google/zxing/*Translator</className>
+    <differenceType>8001</differenceType>
+  </difference>
+</differences>