Circles overlap remover

Remove one or both circles from an overlapping circles pair (with tolerance).

This function includes 3 options to deal with overlaping circles by:
1. remove one circle of the two.
2. removes the smaller circle of the two. 3. kills both all overlaping circles.

This function was used in 'Detecting and Counting Objects with Circular Features' blog post: http://imageprocessingblog.com/detecting-and-counting-objects-with-circular-features/