Few fixes for translations (and translated doc)

• set Your names/Your emails as properties for KAboutData, according the guidelines;
• remove the translated po and the translated docbook, which will be copied to the translation repository (docbooks are going to be converted to po files);
• add a proper Messages.sh;
• add the macro for the installation of translated artifacts, which will be injected using releaseme at release time;
• fix the DTD used for the English documentation.