signed zero

[RobinHankin]

The package implements signed zero...sometimes:

> new("brob", x = -Inf, positive = TRUE)
[1] +exp(-Inf)
> new("brob", x = -Inf, positive = FALSE)
[1] -exp(-Inf)
> new("brob", x = -Inf, positive = TRUE) == new("brob", x = -Inf, positive = FALSE)
[1] FALSE
>

Above, we see new()creating two different brobs, one with positive = TRUE and one with positive = FALSE, and the third line shows that they are not numerically equal. It would be good to document this.