The _overview manpages are not actually commands and hence do not belong
into manpage section 8. Move corosync_overview to section 7
("Miscellaneous") and the other *_overview pages to section 3 as they
contain API documentation (cf. string(3) for precedence of
multi-function manpages).
Signed-off-by: Christoph Berg <myon@debian.org>
Reviewed-by: Jan Friesse <jfriesse@redhat.com>