manager: be more precise in message about restart
man: ignore non-manpage files when generating makefile
build-sys: add conditionals and regenerate manpage list

The list of man pages is auto generated, based on conditonal='...'
attributes in the man page itself.
man: xinclude --help/--version/--no-pager
man: xinclude --user/--system
man: xinclude --host/--machine

As usual, those common options are pushed to the end.
man: xinclude pkg-config note