Won't work with "use strict"

[jinder]

Hi - great work on this library!

Just noticed an issue with your extendDeep function, that prevents it working in strict mode because you're using arguments.callee. The exception I'm getting in chrome is:

"TypeError: 'caller', 'callee', and 'arguments' properties may not be accessed on strict mode functions or the arguments objects for calls to them"

[nissoh]

Thanks. fixed (: