Used to order the cells in an alignment:
-- this > c iff this.getStrength() < c.getStrength() --
public int compareTo( Cell c ){
//if ( ! (c instanceof Cell) ) return 1;
if ( c.getStrength() > getStrength() ) return 1;
if ( getStrength() > c.getStrength() ) return -1;
return 0;
}