Odd 0.7.2 marker behaviour

the resulting tkagg or png output has the triangles

    > pointing in odd directions (sometimes even at 45 degrees).

On line 238 in collection.py, flip the sin and cos order

        self._verts = zip( r*sin(theta), r*cos(theta) )

This was correct in 0.71 but I undid it (wrongly) in 0.72 because the
sin and cos looked to be in the wrong order and I assumed it was a
bug. Now I realize there was a method to my madness, because 0
degrees is pointing up and not to the right....
Something for the bug-fix release! Thanks for the report.