Issue #19: Fix chart series when sheetname contians space.

src/xlsx/xlsxchart.cpp

@@ -104,6 +104,8 @@ void Chart::addSeries(const CellRange &range, AbstractSheet *sheet)
         return;
 
     QString sheetName = sheet ? sheet->sheetName() : d->sheet->sheetName();
+    if (sheetName.contains(QLatin1Char(' ')))
+        sheetName = QLatin1Char('\'') + sheetName + QLatin1Char('\'');
 
     if (range.columnCount() == 1 || range.rowCount() == 1) {
         QSharedPointer<XlsxSeries> series = QSharedPointer<XlsxSeries>(new XlsxSeries);