Added rough main page and header design layout

Added rough main page and header design layout
    application/controllers/pages.php
    application/models/header_model.php (+)
    application/models/navbar_model.php (-)
    application/views/footer.php
    application/views/header.php
    application/views/pages/home.php
    css/layout.css
    css/skeleton.css
    css/style.css
    images/keywords-100.png             (+)
    images/sofa.png                     (+)
    images/title-100.png                (+)