Merge pull request #1770 from uhafner/ignore-serializable-loose-coupling

Ignore `LooseCoupling` rule for serializable objects

Author: uhafner

etc/pmd-java-configuration.xml

@@ -21,6 +21,7 @@
   <rule ref="category/java/bestpractices.xml/LooseCoupling">
     <properties>
       <property name="allowedTypes" value="java.util.Properties, java.util.Stack, java.util.jar.Attributes, net.minidev.json.JSONArray, hudson.util.ListBoxModel, hudson.util.ComboBoxModel, hudson.DescriptorExtensionList, hudson.EnvVars,  org.jsoup.select.Elements, edu.hm.hafner.util.LineRangeList" />
+      <property name="violationSuppressXPath" value="./ancestor::ClassDeclaration[1][pmd-java:typeIs('java.io.Serializable')]"/>
     </properties>
   </rule>
   <rule ref="category/java/codestyle.xml">