Fixes webfonts, resolves 'smcp' opentype feature

The Fontdeck css calls the primary font 'Premiera Book' instead of 'Premiera' or 'Premiera Regular, which was causing the main body font to render 'Georgia'.

As a side-effect, small caps were also not getting rendered. The 'Premiera Italic' font doesn't seem to be the OpenType variant, so `abbr` wasn't able to use `font-feature-settings:"smcp" 1, "onum" 1;`. Altered the styles to render 'Premia Book' in these situations too.

This will resolve #6.