Sets namespace string on obj and makes namespace configurable (@see Object.defineProper(ty|ties)).
@param ns_string {String} - Namespace string; E.g., 'all.your.base'
@param objToSearch {Object} - Object to set namespace string on.
@param valueToSet {*|undefined} - Value to set at end of namespace string.
@returns {*} - Value that was set at the end of the namespace propagation.
function unConfigurableNamespace(ns_string, objToSearch, valueToSet) {
        var parent = objToSearch,
            shouldSetValue = typeof valueToSet !== _undefined,
            hasOwnProperty;

        ns_string.split('.').forEach(function (key, i, parts) {
            hasOwnProperty = parent.hasOwnProperty(key);
            if (i === parts.length - 1
                && shouldSetValue && !hasOwnProperty) {
                defineEnumProp(parent, key, valueToSet);
            }
            else if (typeof parent[key] === _undefined && !hasOwnProperty) {
                defineEnumProp(parent, key, {});
            }
            parent = parent[key];
        });

        return parent;
    }