Added profiles for custom layouts.

Users can add severals custom layouts and select one of them in recording fragment. The last selected layout is the one that will be use in the next recording.
Fixes #938.

src/main/java/de/dennisguse/opentracks/util/StatisticsUtils.java

@@ -25,7 +25,7 @@ public class StatisticsUtils {
     }
 
     public static Layout filterVisible(Layout layout, boolean visible) {
-        Layout result = new Layout(layout.getProfile());
+        Layout result = new Layout(layout.getName());
         result.addFields(layout.getFields().stream().filter(f -> f.isVisible() == visible).collect(Collectors.toList()));
         return result;
     }