Browsers such as Chrome and Firefox apply an arbitrary scale to the
current font size if `normal` is used for `line-height`. Firefox uses
1.2 while Chrome uses 1.15. Let's go with the latter for now, it's
relatively easy to change if we ever want to go back on that decision.
This also requires updating the expectations for a lot of layout tests.
The upside of this is that it's a bit easier to compare our layout
results to other browsers', especially Chrome.
Like 1132c858e9, out-of-flow elements such
as float elements would get inserted into block level `::before` and
`::after` pseudo-element nodes when they should instead be inserted as a
sibling to the pseudo element. This change fixes that.
This fixes a few layout issues on the swedish tax agency website
(skatteverket.se). :^)