fix: clone() cloning prototype's custom methods

[jettcalleja]

clone method in common.js will also clone the prototype custom methods

var a = [1,2];
Array.prototype.try = function() {return true;};
winston.info(a);  // info:  0=1, 1=2, try=function () {return true;}

[indexzero]

It's generally considered a bad practice to modify the Array prototype. Will consider landing this on the 2.x branch after [email protected] hits the wild in about a week.

[jettcalleja]

I agree it is a bad practice, but I did this to catch this modifying prototypes and avoid logging them. Thanks for the consideration!

[jettcalleja]

@indexzero travis-ci became fail, will this be landing on the 2.x?