Made it possible to add a css class
alt attribute can now be changed
Fixed: "else if" and "elseif" is not the same.
Improved comments
Separated implementation to own file Libravatar.body.php.
Fixed check of user existence (previously an invalid email address was reported when the user did not exist).
Internationalization: Created i18n file and did en and de translation.
Increased version number (no release yet because documentation has to be updated as well).