Agg backend doesn't draw line to arc start point

[corranwebster]

Given:

x, y = 100, 100
gc.begin_path()
gc.move_to(x - 12, y - 12)
gc.arc(x, y, 12.0, 0.0, np.pi)
gc.line_to(x - 12, y - 12)
gc.draw_path()

Compare Agg:

vs. Quartz:

From the documentation:

enable/kiva/basecore2d.py

Lines 607 to 609 in bb2c358

	If there is a current path and the current point is not the initial
	point of the arc, a line will be drawn to the start of the arc. If
	there is no current path, then no line will be drawn.