Improved view: welcome_message.php - 2nd try

Various changes, solved some w3 validator warnings and erros, edited js for mobile menu (using toggle instead of if/else), some margin/padding and color adjustment about mobile navigation and a bit of css transitions for css hover effects. Cursor pointer on toggle menu button/link. I think both validator and graphic changes improve the current one. Fixed reverse menu items on mobile or desktop version.

Author: Gianluigi Vizzielli