Fix incompatibility with zii via @rvagg's fix

[KyleMaas]

See #80 (comment)

Tested with and without zii, and works in both cases.

Fixes #80.

[KyleMaas]

Hm. This worked on the command line.

[rvagg]

Fine by me, calling it by Object.prototype is not really necessary since we control the creation of these objects, but whatever.
@hugomrdias I think you'd better review the typing here, I don't think @type {BaseName} is going to work here is it since hasOwnProperty expects a string argument. I'm not sure what should be done, maybe remove the type annotation all together? We don't seem to have any type checking in the scripts here yet that can tell us easily.

[KyleMaas]

Fine by me, calling it by Object.prototype is not really necessary since we control the creation of these objects, but whatever.

The Object.prototype stuff was because the linter complained about it if I tried to use hasOwnProperty directly on the object. If there's a better way to do that without failing the linter, go for it.

[rvagg]

because the linter

Ahh, right, well that's become the standard "safe" pattern of calling it to ensure that you can call it on any object. Fair enough, it's like being forced to use === when you know == is enough in a particular instance--still good practice.

[hugomrdias]

LGTM thank you all for the help.

[KyleMaas]

Excellent. Thank you!