Right now, 'man libvirtd' includes information that depends on
configure results, so it must be generated on the fly and live
in $(builddir); however, requiring pod2man on all end user
machines is overkill.  Meanwhile, 'man virsh' doesn't mention
any configure results, so it can be built at 'make dist' time.
If that situation changes in the future, we can generate virsh.1
in the same way that we generate libvirtd.8.

* daemon/Makefile.am (libvirtd.8.in): New rule, to run pod2man in
advance of distribution.
(libvirtd.8): Use only sed from tarball.
(EXTRA_DIST): Ship new file.
(libvirtd.pod): Delete unused rule.
(man8_MANS): Let automake know which section to use.
(CLEANFILES, MAINTAINERCLEANFILES): Adjust to new files.
* tools/Makefile.am (dist_man1_MANS): Distribute pre-built man
pages, fine since they don't require any substitution.
(virt-xml-validate.1, virt-pki-validate.1): Change input source.
(virsh.1): Build into srcdir.
(CLEANFILES, MAINTAINERCLEANFILES): Adjust to new build style.
* daemon/.gitignore: Update.
Reported by Diego Elio Pettenò.