Set font selection order for face font selection to ORDER.
ORDER must be a list of length 4 containing the symbols `:width',
`:height', `:weight', and `:slant'. Face attributes appearing
first in ORDER are matched first, e.g. if `:height' appears before
`:weight' in ORDER, font selection first tries to find a font with
a suitable height, and then tries to match the font weight.
Value is ORDER. (fn ORDER)