Scrub string.js.

Will probably be retired in favor of Node reusables.

src/utils/string.js

@@ -1,6 +1,5 @@
 /**
 Definitions of string utility functions.
-@license MIT. Copyright (c) 2015 James Devlin / FluentDesk.
 @module string.js
 */
 
@@ -10,6 +9,8 @@ See: http://stackoverflow.com/a/32800728/4942583
 @method isNullOrWhitespace
 */
 
+(function() {
+
   String.isNullOrWhitespace = function( input ) {
     return !input || !input.trim();
   };
@@ -21,3 +22,5 @@ String.prototype.endsWith = function(suffix) {
   String.is = function( val ) {
     return typeof val === 'string' || val instanceof String;
   };
+
+}());