Automated code analysis improvements.

src/main/java/de/dennisguse/opentracks/io/file/exporter/FileTrackExporter.java

@@ -206,7 +206,7 @@ public class FileTrackExporter implements TrackExporter {
      *
      * @author Jimmy Shih
      */
-    private class TrackWriterTrackPointFactory extends TrackPointFactory {
+    private static class TrackWriterTrackPointFactory extends TrackPointFactory {
         TrackPoint currentTrackPoint;
         TrackPoint lastTrackPoint;
 

src/main/java/de/dennisguse/opentracks/io/file/importer/AbstractFileTrackImporter.java

@@ -464,7 +464,7 @@ abstract class AbstractFileTrackImporter extends DefaultHandler implements Track
      * @author Jimmy Shih
      */
     // TODO Why private inner class?
-    private class TrackData {
+    private static class TrackData {
         // The current track
         final Track track = new Track();
 

src/main/java/de/dennisguse/opentracks/io/file/importer/KmlFileTrackImporter.java

@@ -297,7 +297,7 @@ public class KmlFileTrackImporter extends AbstractFileTrackImporter {
         }
         float value;
         try {
-            value = Float.valueOf(content);
+            value = Float.parseFloat(content);
         } catch (NumberFormatException e) {
             throw new SAXException(createErrorMessage("Unable to parse gx:value:" + content), e);
         }