Tick labels can appear past the end of the axis when tick values are given explicitly

As can be seen in [this](http://jsfiddle.net/g055bk5d/) JSFiddle, if x-axis tick values are provided, and a y-axis label is positioned outside the graph area, a tick label can become positioned past the left end of the x-axis.

A similar thing can happen on the right side when the legend is positioned outside the graph area.

Looks like rendering of explicit tick values needs to take into account the actual graph area rather than the whole area of the containing element.