Remove duplicate entries under "Additional IO v2 pins" in iov2
and add missing periods at the end of sentences in both io(1) and iov2(1)
to make sure the identical strings stay the same to save translators
duplicate work.
Some manual pages uses roff macros and other features not handled by
po4a. Make more manual pages translatable by removing the use of such
macros where it is trivial to do.
