Note that the multirow package is needed for rowspans.
It is included in the latex template under a variable,
so that it won't be used unless needed for a table.
The 3 native table test cases are normalized so that it will looks exactly like it is written by some pandoc writers.
Note that apart from white space normalization, it includes other normalization such as `[Str "Nordic countries"] to [Str "Nordic",Space,Str "countries"]`.
