CMSPLT-23 : Fix harcoded messages and adapt texts to the last version of CKEditor

Fix hardcoded messages on configureContent.jsp

The "Edit" link depends on fluid project : https://github.com/fluid-project/infusion/tree/infusion-1.4/src/webapp/components/inlineEdit/

The content area can't be edited by clicking : http://fluidproject.org/releases/1.4/demos/inlineEdit/rich/html/inlineEdit.html