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.
1) Use num-wording in the manpage, remove offensive remark against
the beloved -num-syntax <3.
2) Style changes.
3) Report errors of getline.
4) argv-argc-centric argument loop.
5) Rename r to ret for consistency.
- add .Os, it is mandatory.
- don't redeclare .Nm when it's not needed.
- fix some warnings (checked with mandoc -Tlint).
- remove some leftover old stuff.
