Determines whether user specified breaks for histograms are properly ordered
and match the left and right truncation.
     
    
    Usage
    test.breaks(breaks, left, width)
 
    
    Arguments
- breaks
- vector of cutpoints (breaks) for distance histogram 
- left
- left truncation value 
- width
- right truncation value; either radius of point count or
half-width of transect 
 
    
    Value
    vector of breaks modified to be valid if necessary