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.
This essentially reverts 1b46a52cfc
and adds more tests.
The reverted change was an incorrect workaround for the real issue,
which was that we weren't creating anonymous wrapper boxes around inline
children of table-cell boxes.
Now that this has been fixed, we can go back to aligning text properly.
