Update ckeditor

GPL 3 compliant


 * Already have a plugin for LimeSurvey (need update),
 * Have a "placehoder" system to take inspiration :http://ckeditor.com/latest/samples/plugins/placeholder/placeholder.html
 * Upload/link to file (width kcfinder)
 * Image upload (width kcfinder)
 * i18n
 * Files upload plugin or integration :
 * kcfinder : last git move are 27 Sep 2014
 * roxyfileman
 * elFinder
 * http://ckeditor.com/addon/imgupload