Enable several more checkstyle modules

* Enable checkstyle ParenPadCheck
* Enable checkstyle EmptyLineSeparator
* Enable checkstyle TypecastParenPad

airsonic-main/src/main/java/org/airsonic/player/ajax/TransferService.java

@@ -25,6 +25,7 @@ import org.directwebremoting.WebContextFactory;
 import org.springframework.stereotype.Service;
 
 import javax.servlet.http.HttpSession;
+
 /**
  * Provides AJAX-enabled services for retrieving the status of ongoing transfers.
  * This class is used by the DWR framework (http://getahead.ltd.uk/dwr/).

airsonic-main/src/main/java/org/airsonic/player/i18n/LocaleResolver.java

@@ -32,6 +32,7 @@ import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Locale;
 import java.util.Set;
+
 /**
  * Locale resolver implementation which returns the locale selected in the settings.
  *

airsonic-main/src/main/java/org/airsonic/player/service/metadata/DefaultMetaDataParser.java

@@ -40,6 +40,7 @@ public class DefaultMetaDataParser extends MetaDataParser {
     public DefaultMetaDataParser(SettingsService settingsService) {
         this.settingsService = settingsService;
     }
+
     /**
      * Parses meta data for the given file.
      *

checkstyle.xml

@@ -21,13 +21,20 @@
             <property name="separateLineBetweenGroups" value="true"/>
         </module>
         <module name="DefaultComesLast"/>
+        <module name="EmptyLineSeparator">
+            <!-- Enable all except PACKAGE_DEF, METHOD_DEF, VARIABLE_DEF -->
+            <property name="tokens"
+                      value="IMPORT, STATIC_IMPORT, CLASS_DEF, INTERFACE_DEF, ENUM_DEF, STATIC_INIT, INSTANCE_INIT, CTOR_DEF"/>
+        </module>
         <module name="EmptyStatement"/>
         <module name="EqualsAvoidNull"/>
         <module name="EqualsHashCode"/>
         <module name="Indentation"/>
         <module name="InnerAssignment"/>
+        <module name="ParenPadCheck"/>
         <module name="RedundantImport"/>
         <module name="StringLiteralEquality"/>
+        <module name="TypecastParenPad"/>
         <module name="UnusedImports"/>
     </module>
 </module>