sprinkle some Xr; from josiah frentsos

use fancy .In macro for includes. from Jan Klemkow. ok jmc schwarze

convert to new .Dd format;

- make sure sem_ pages reference each other (idea from similar freebsd commit)

- where two functions are documented in the same page, make sure we don;t
reference them both in SEE ALSO. kind of anno

- make sure sem_ pages reference each other (idea from similar freebsd commit)

- where two functions are documented in the same page, make sure we don;t
reference them both in SEE ALSO. kind of annoying to call up a second man
page and find it's the same as the last one (even more annoying to not
realise two pages are the same till you've finished reading twice ;)...

show more ...

- typos
- new sentence, new line
- clean up .Xrs

fix includes and some cleanup.

sem_XXX(3) manpages; better now that never.
From FreeBSD.