Refactor: Follow Qt5 module's file directories style

Xlsx Shared library can be used now

examples/xlsx/hello/hello.pro

@@ -0,0 +1,6 @@
+TARGET = hello
+
+#include(../../../src/xlsx/qtxlsx.pri)
+QT+=xlsx
+
+SOURCES += main.cpp

examples/xlsx/hello/main.cpp

@@ -0,0 +1,37 @@
+#include <QtCore>
+#include "xlsxworkbook.h"
+#include "xlsxworksheet.h"
+
+#ifdef Q_OS_MAC
+#  define DATA_PATH "../../../"
+#else
+#  define DATA_PATH "./"
+#endif
+
+int main()
+{
+    QXlsx::Workbook workbook;
+    QXlsx::Worksheet *sheet = workbook.addWorksheet();
+    sheet->write("A1", "Hello Qt!");
+    sheet->write("B3", 12345);
+    sheet->write("C5", "=44+33");
+    sheet->write("D7", true);
+
+    QXlsx::Worksheet *sheet2 = workbook.addWorksheet();
+    //Rows and columns are zero indexed.
+    //The first cell in a worksheet, "A1", is (0, 0).
+    sheet2->write(0, 0, "First");
+    sheet2->write(1, 0, "Second");
+    sheet2->write(2, 0, "Third");
+    sheet2->write(3, 0, "Fourth");
+    sheet2->write(4, 0, "Total");
+    sheet2->write(0, 1, 100);
+    sheet2->write(1, 1, 200);
+    sheet2->write(2, 1, 300);
+    sheet2->write(3, 1, 400);
+    sheet2->write(4, 1, "=SUM(B1:B4)");
+
+    workbook.save(DATA_PATH"Test.xlsx");
+    workbook.save(DATA_PATH"Test.zip");
+    return 0;
+}