We should stop treating floating ::first-letter frames as floats using our standard float code. I think the designers of CSS (in this case, Håkon Lie) intended floating first-letter to be "like a float" but not "exactly a float". We should: * make floating :first-letter participate in inline layout * use the bounding metrics of the glyph(s) to size the frame * give it a special hard-coded 'vertical-align' (probably roughly 'text-top') * make it not participate in line-height calculations * mark the space as occupied in the space manager