Window centroid culling method change.

In ics_mcsActor/python/mcsActor/windowCentroid/centroid_win.c, there is code related to the situation if there are multiple spots detected within a certain radius. The multiple detection happened due to

1. The default kernel is smaller than the actually spot size
2. Multi-processing when processing smaller pieces of the whole image.

Current code just eliminate sources based on distance, we need to make sure this culling method is working for all cases.

	  if(rs < rmin)
	    {
	      /*We want to delete the second node - they are either the same point, duplicated,
		or the second point is fainter than the first*/
	      if((p1 >= p2))  //delete pointed to node
		{

		  if(check_val->next != NULL)  //Not the last node
		    {
		      check_pre->next=check_val->next;
		      check_pre=check_val->next;
		      check_val=check_pre->next;
		    }