Test range of Date values

[Richard Gomes]

I stumbed with a question regarding the internal representation of Date values.

private /*@NonNegative*/ int value;

static private final int MinimumSerialNumber = 367; // 01-Jan-1901
static private final int MaximumSerialNumber = 73050; // 31-Dec-2099

It's a good idea to test if these limits are really working as expected. I mean: there's a possibility that it does not work as expected due to the fact Java does not provide unsigned data.