protected void setUserDefinedFolder(@Nullable final Folder userDefinedFolder, final boolean setByUser) {
        this.userDefinedFolder = userDefinedFolder;
        Settings.setPersistableFolder(this, userDefinedFolder == null ? null : userDefinedFolder.toConfig(), setByUser);
        notifyChanged();
    }
Sets a new user-defined location (or "null" if default shall be used). Should be called ONLY by {@link ContentStorage}
main/src/main/java/cgeo/geocaching/storage/PersistableFolder.java