Imporved language switching.

Imporved language switching by basing it off of the REQUEST_URI.

It simply assumes that any /no/ in the URI can safely be converted to a /en/ and
vice versa.

    application/views/header.php
Added PayPayl IPN secret word

Added PayPayl IPN secret word, which is used to confirm that access is being
done by paypal and not someone else. Payment should still be authenticaded with
paypal, but this is a cheap and easy way to add another layer.

    application/config/orig-secureconfig
    generate/gen-orig-downloadconfig.php -> generate/gen-orig-secureconfig.php
Improved music page. New buttons, translations.

Improved music page:
 - New buttons for 'listen' and 'buy'.
 - Added English translations to tv projects.

    application/models/music_model.php
    application/views/pages/music.php
    css/music.css
    images/icons/buy-white-20.png   (+)
    images/icons/listen-black-20.png   (+)
    images/icons/listen-white-20.png   (+)