In 2.11.3 we started adding `\addlinespace`, which produced less
dense tables. This wasn't an intentional change; I misunderstood
a comment in the discussion leading up to the change. This commit
restores the earlier default table appearance.
Note that if you want a less dense table, you can use something like
`\def\arraystretch{1.5}` in your header.
Closes#6996.
+ Remove the `\strut` that was added at the end of minipage
environments in cells.
+ Replace `\tabularnewline` with `\\ \addlinespace`.
Closes#6842, closes#6860.
Note that if the table has a first page header and a
continuation page header, the notes will appear only
on the first occurrence of the header.
Closes#2378.