Convex Hull: we must break ties for the right-most point too

[thomas3494]

We must break ties on the right-most point as well to avoid reporting a colinear point. A counter example is

pbbs_sequencePoint2d
1,  0
1,  1
1, -1
0,  0

which represents the following points (number is order)

     1
3    0
     2

It should report 3, 1, 2, but reports 3, 1, 0, 2.