private void lazyInitPreferenceKeys() {
        if (basicPreferences[0] == null) {
            for (int i = 0; i < basicPreferencesInt.length; i++) {
                basicPreferences[i] = CgeoApplication.getInstance().getString(basicPreferencesInt[i]);
            }
        }
    }
searches recursively in all elements of given prefGroup for first occurrence of s
returns found preference on success, null else
(prefers preference entries over preference groups)
main/src/main/java/cgeo/geocaching/settings/fragments/BasePreferenceFragment.java