Add ability to rotate labels

[ArtBIT]

var xAxis = new Rickshaw.Graph.Axis.X({
    graph: graph ,
    tickRotation: 90,
    tickOffsetX: -10
});
xAxis.render();

[dchester]

This is cool -- but labels are rotated about their top right corner rather than about the end of the baseline. Let's see if we can find a way to avoid users having to tweak placement every time with x and y offsets.

[pkpp1233]

How might I rotate labels at all? Can't find that in the api.

[ikari-pl]

Please merge this, I kinda need it! :)

[cmullenmm]

+1 for this

[draj0]

+1