Merged WWW/YoutubeViewer/AuthToken.pm into WWW/YoutubeViewer.pm
Now, the new access token is saved into the authentication file right after it is recieved.
Removed the support for access_token and refresh_token configuration keys.
Removed the support for the very old config file style which consisted only of a HASH ref.
GTK Youtube Viewer has a new awesome icon. (thanks to posixru - http://zenway.ru/)