Make RichString public

tests/auto/richstring/tst_richstringtest.cpp

@@ -1,4 +1,4 @@
-#include "private/xlsxrichstring_p.h"
+#include "xlsxrichstring.h"
 #include <QtTest>
 #include <QDebug>
 

tests/auto/sharedstrings/tst_sharedstringstest.cpp

@@ -1,5 +1,5 @@
 #include "private/xlsxsharedstrings_p.h"
-#include "private/xlsxrichstring_p.h"
+#include "xlsxrichstring.h"
 #include "xlsxformat.h"
 #include <QString>
 #include <QtTest>

tests/auto/worksheet/tst_worksheet.cpp

@@ -8,7 +8,7 @@
 #include "private/xlsxworksheet_p.h"
 #include "private/xlsxxmlreader_p.h"
 #include "private/xlsxsharedstrings_p.h"
-#include "private/xlsxrichstring_p.h"
+#include "xlsxrichstring.h"
 
 class WorksheetTest : public QObject
 {