"bottom" vertical alignment text position is off by one line

[SheetJSDev]

Demo: http://jsfiddle.net/hawoc9tL/

The text for the cells is not visible since the y position is off.

https://github.com/TonyGermaneri/canvas-datagrid/blob/master/lib/draw.js#L638 the baseline would start at the top of the calculated box. It should be shifted down by the height of the the first line of text. Mirroring the "top" case:

        vPos = cell.height - cell.paddingBottom - cell.text.height + cell.calculatedLineHeight;