Fixed issue where widget position would be overwritten on gridmap

This fixes an issue where widget position would be overwritten on gridmap inside add_faux_cell ().

To reproduce add these widgets in the following order:
```javascript
gridster.add_widget('<li class="new">The HTML of the widget...</li>', 2, 1, 1, 2);
gridster.add_widget('<li class="new">The HTML of the widget...</li>', 2, 1, 1, 3);
gridster.add_widget('<li class="new">The HTML of the widget...</li>', 2, 1, 1, 1);
```

The grid wrapper will only wrap around the 3rd element, with the first two overflowing. It's easiest to see by adding some background colours to the elements and wrapper.