Update LoaderParser.js (remove navigator.isCocoonJS)

Safe to remove "navigator.isCocoonJS" here since CocoonJS doesn't have a window.DOMParser object, nor will a createElement('div') work under Accelerated Canvas/WebGL mode anyway. CocoonJS' createElement is limited to only 'img',  'image',  'audio',  'canvas', and 'screencanvas' elements.*

(Under WebView mode, there is a high likelihood of DOMParser existing too. Most browsers have it.)

*Reference: http://support.ludei.com/hc/en-us/articles/200807787-HTML5-feature-list