added option to include an additional right aligned title label to rowChart. _chart.renderTitleLabel.  Fixed minor typo in API documentation.

This is an alternative (or can be used in addition to) the tooltip rendering for "title" .

example here:
http://jsfiddle.net/jeffsteinmetz/49WYd/

below is an example usage of renderTitleLabel and titleLabelOffsetX:

```
sampleRowChart.width(200)
        .height(275)
        .margins({top: 0, right: 10, bottom: 0, left: 10})
        .dimension(yourDim)
        .group(yourGroup)
        .label(function (d) {
            return d.key;
        })
        .title(function (d) {
            return d.value;
        })
        .renderTitleLabel(true)  // show titles (values) with text-anchor 'end'
        .titleLabelOffsetX(3);
```