Fix ordering option for the barChart.

Fix the bug: ordering not working on barChart.

If you write in the barChart definition:

1. **chart.ordering(function (d) { return  d.data.value;   });** 
It will order the barChart xAxis by value increasing.

2. **chart.ordering(function (d) { return  -d.data.value;   });** 
It will order the barChart xAxis by value decreasing.

3. **chart.ordering(function (d) { return  d.data.key;   });** 
It will order the barChart xAxis by key, alphabetical order.