Refactor: Follow Qt5 module's file directories style

Xlsx Shared library can be used now

src/xlsx/xlsxworkbook_p.h

@@ -0,0 +1,58 @@
+/****************************************************************************
+** Copyright (c) 2013 Debao Zhang <hello@debao.me>
+** All right reserved.
+**
+** Permission is hereby granted, free of charge, to any person obtaining
+** a copy of this software and associated documentation files (the
+** "Software"), to deal in the Software without restriction, including
+** without limitation the rights to use, copy, modify, merge, publish,
+** distribute, sublicense, and/or sell copies of the Software, and to
+** permit persons to whom the Software is furnished to do so, subject to
+** the following conditions:
+**
+** The above copyright notice and this permission notice shall be
+** included in all copies or substantial portions of the Software.
+**
+** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+** NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+** LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+** OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+** WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**
+****************************************************************************/
+#ifndef XLSXWORKBOOK_P_H
+#define XLSXWORKBOOK_P_H
+#include "xlsxworkbook.h"
+
+namespace QXlsx {
+
+class WorkbookPrivate
+{
+    Q_DECLARE_PUBLIC(Workbook)
+public:
+    WorkbookPrivate(Workbook *q);
+
+    Workbook *q_ptr;
+
+    SharedStrings *sharedStrings;
+    QList<Worksheet *> worksheets;
+    Styles *styles;
+
+    bool strings_to_numbers_enabled;
+    bool date1904;
+
+    int x_window;
+    int y_window;
+    int window_width;
+    int window_height;
+
+    int activesheet;
+    int firstsheet;
+    int table_count;
+};
+
+}
+
+#endif // XLSXWORKBOOK_P_H