Border drawn over horizontal label in DotLinePlot

[Sebastien Cote]

When generating a DotLinePlot with a horizontal label and the text is short, the bottom border of the graph is often drawn over the text.

This issue can be reproduced with the following test case:

test_data = [0, 100]
h_label = ['0', '100']
CairoPlot.dot_line_plot('test', test_data, 400, 300, axis = True, grid = True, h_legend = h_label)