KnockoutProperty.createArrayMethod should no longer splice the property array.

[briandipalma]

Inside KnockoutProperty we have this code,

KnockoutProperty.createArrayMethod = function(sMethod) {
    return function() {
        var pUnderlyingArray = this.getValue();
        var pNewArray = pUnderlyingArray.splice(0, pUnderlyingArray.length);
        Array.prototype[sMethod].apply(pNewArray, arguments);
        this.setValue(pNewArray);
    };
};

Which performs a splice on the KO property array. This means that an array provided to the property would end up being mutated during any array operation performed on the property. When creating a
Property and providing it an array you might be surprised to see the array you provided mutated. This array
could be an array of application wide configuration for example, which when modified could lead to weird
bugs. Does it seem reasonable to instead do a slice on the array, thus preserving the original array?