Label rotation is sub-optimal.

[snakeru]

I thought of fixing it myself, but it proved to be not a 15-minute task, so I'll just leave a feature request here: The label rotation rotates only the text inside it, but the label itself stays horizontal, only changing the height/width to accomodate the rotated text:

Style: chart.Style{
				FillColor:   drawing.Color{1, 255, 3, 10},
				StrokeColor: drawing.Color{255, 6, 7, 20},
				StrokeWidth: 0,
				FontSize:    10,
				TextRotationDegrees:-90,
			},

UPDATE: after I increased the font size another problem popped up: the text seems to be not properly aligned. But for me that is fine as I use font size 5 and there it is almost OK.

[snakeru]

The initial idea was to rotate it 45 degrees, btw, but it was not much better: