Comment 2 for bug 1209790

The following link describes more about floating pointer in Java:

http://www.concentric.net/~Ttwang/tech/javafloat.htm

In particular, I'm in doubt if we should use Double.NaN, Double.POSITIVE_INFINITY or Double.MAX_VALUE.

Anyway, whatever decision is made, we will have to revisit the entire code, looking for places where we have test for Double.NaN and eventually substitute by something else. We will also have to revisit class Closeness