Updating labels should update tooltips

[gkrinc]

When I change the data in the it renders and shows the updated data but the tooltip labels are wrong...they're always showing the first x-axis label: http://stackoverflow.com/questions/35447775/why-are-the-chartjs-tooltip-labels-always-showing-the-first-x-axis-label

Setting redraw to true resolves the issue, but this seems like a weird approach.

[MathiasLund]

+1