[PDN 3.2α2] Open arrowhead points in the wrong direction

[Joey]

The open (cf. filled) arrowheads may point in the wrong direction.

Steps to reproduce:

1. choose line/curve tool, select »Arrow« from the end cap list (»Filled Arrow« works as intended)

2. draw a line

3. make a curve from the line. Drag the nubs with the left (i. e. primary) mouse button, since it works correctly with Bézier curves (as tangent calculation is easier)

4. play around a bit and watch the arrowhead point a way different from the line.

This end cap is probably self-drawn (as it bears little resemblance to the filled arrow, which may be from .NET's line drawing facilities) and it will point the same way a line would point when drawn through the last control point and the end point (which is fine for Béziers as that _is_ the tangent in the end point but not for cardinal splines).