Replace StringUtils.join() with library call

Use Apache commons.lang3 instead of own implementation.

Author: Pieter12345

app/test/processing/app/helpers/StringUtilsTest.java

@@ -29,6 +29,7 @@
 
 package processing.app.helpers;
 
+import org.apache.commons.lang3.StringUtils;
 import org.junit.Test;
 
 import static org.junit.Assert.assertEquals;

arduino-core/src/cc/arduino/packages/discoverers/PluggableDiscovery.java

@@ -36,6 +36,8 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import org.apache.commons.lang3.StringUtils;
+
 import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility;
 import com.fasterxml.jackson.annotation.PropertyAccessor;
 import com.fasterxml.jackson.core.JsonFactory;
@@ -48,7 +50,6 @@
 import cc.arduino.packages.BoardPort;
 import cc.arduino.packages.Discovery;
 import processing.app.PreferencesData;
-import processing.app.helpers.StringUtils;
 
 public class PluggableDiscovery implements Discovery {
 

arduino-core/src/cc/arduino/packages/uploaders/SSHUploader.java

@@ -44,7 +44,6 @@
 import processing.app.helpers.PreferencesMap;
 import processing.app.helpers.PreferencesMapException;
 import processing.app.helpers.StringReplacer;
-import processing.app.helpers.StringUtils;
 
 import java.io.File;
 import java.io.IOException;
@@ -54,6 +53,8 @@
 import java.util.List;
 import java.util.Set;
 
+import org.apache.commons.lang3.StringUtils;
+
 import static processing.app.I18n.tr;
 
 public class SSHUploader extends Uploader {

arduino-core/src/processing/app/helpers/StringUtils.java

@@ -15,12 +15,4 @@ public static String rtrim(String s) {
     }
     return s.substring(0, i + 1);
   }
-
-  public static String join(String[] arr, String separator) {
-    StringBuffer sb = new StringBuffer();
-    for (String s : arr) {
-      sb.append(s).append(separator);
-    }
-    return sb.substring(0, sb.length() - separator.length());
-  }
 }