Parameter pm in class fib_param2 not needed

I've taken out the variable that recorded pm = +/-1, since the parameterisation no longer uses it. I've done a test render of one frame at cloud.sagemath with the suggested code

sage: a = BaseSpiral(1,(0,pi/2),(pi,0),'sph', include_final=True)
sage: draw_frame(a.points(), n=0, high_quality=True, only_show=False)

and it works fine.