Mostly manpage-shuffling according to the changes in the corrigendum,
wording changes and more idiomatic expressions.
All this is finished up by marking the POSIX 2013 conformant tools
with
.St -p1003.1-2013
which is not available in older mandoc builds or nroff, but which
reflects what we actually did, so who cares?
This is a huge step and it's not far until we can release sbase 0.1.