Feature/codepreitty Syntax Highlighting in preview mode

Contributing document based pull request (I forgot writing commit messge with ticket number.sorry)

customized google-code-prettify addon work with jake except lint. (google-code-prettify is not JSHint friendly code. To pass JSHint, Fix ALL google-code-prettify code)

If include epiceditor.codeprettify.js before epiceditor.js, Syntax highlighting in preview mode is enabled.
else, It work as original EpicEditor.