add all ip 0.0.0.0 to isPrivate and isLoopback

[littleskunk]

#50

[lilyannehall]

I think practically it makes sense to treat 0.0.0.0 this way, but technically since it's a meta-address that means "all available ipv4 addresses" its not really a loopback or private IP. I wonder if there should be an additional method like isRoutable that checks for this instead of classifying it as a loopback interface.

[littleskunk]

I agree on that as long as the ipv6 equivalent :: is treated the same way.

I will wait for a decision.