Emoji in colour, sized as in the reference browser

Every emoji on a page showed as an empty box: the system's emoji font was never among the fonts Floati could fall back to, and its glyphs are pictures that a text renderer cannot draw. Now, on macOS, the emoji font joins every page, each emoji is drawn from its picture, and runs that hold one are painted in software where the graphics card path only knows outlines. (Windows follows once its layered colour emoji are drawn.) Loading the font costs nothing extra: Floati reads only the few tables it needs to lay text out, and a picture only when it is drawn.

Measured in the reference browser at every size from 6 to 40px, small emoji are set a little larger than the text around them (a quarter larger up to 16px, back to the text size by 24px) and on whole pixels, and a line holding one grows to the emoji's own height. Floati now does exactly that, so text around emoji wraps and stacks where it does there.