title: Copying block of data in SpreadsheetView to a bigger block does not work
body: <p>I am using the <code>SpreadsheetView</code> from ControlsFX. When I select multiple cells, copy them and paste them to a bigger block it does not work.</p>
  
  <p>My code: </p>
  
  <pre><code>int rowCount = 5;
  int columnCount = 3;
  GridBase grid = new GridBase(rowCount, columnCount);
  
  ObservableList&lt;ObservableList&lt;SpreadsheetCell&gt;&gt; rows = FXCollections.observableArrayList();
  
  for (int row = 0; row &lt; grid.getRowCount(); ++row) {
      final ObservableList&lt;SpreadsheetCell&gt; list = FXCollections.observableArrayList();
      for (int column = 0; column &lt; grid.getColumnCount(); ++column) {
          list.add(SpreadsheetCellType.STRING.createCell(row, column, 1, 1,"value"));
      }
      rows.add(list);
  }
  
  grid.setRows(rows);
  spreadsheet.setGrid(grid); 
  </code></pre>