Re: std.uuid: Update 3

[Tobias Pankrath]

There are some references to a nilUUID left and the intro says, 
that UUIDs default to nil. I'd recommend not to use nil at all 
and instead talk about an empty UUID or UUID.init. The intro 
should state that an UUID is empty iff it eqauls UUID.init and 
that UUID.init is an UUID with all bytes zero.