Test more of the syntax of the font: shorthand.
Setting the font: shorthand to something like smaller is not in line with the css spec. Just set the font-size: property for this. Also fix the other font: shorthand to specify size and family according to the css spec.
This reverts commit a4ed154b03. The misparsing that is tested here will not be fixed in 3.20, so keep this test out of the stable branch.
a4ed154b03