For OCaml tools this does essentially nothing useful because the
--help output is automatically generated from the options, and so
cannot be wrong. However for C tools this is a useful check.
It would be nice to generate C tools --help output, but there isn't
enough information in the getopt data to do that.
This commit also includes fixes to the --help output for a few tools.
podcheck.pl is run as part of the tests to perform various checks on
the documentation and the tool.
Currently we check only that the documented options matches the
options that the tool implements and vice versa. This commit would
also allow us (in future) to check --help, --long-options,
--short-options, --version output.
This commit includes scripts to run the tests and various fixes to the
manual pages to ensure that the tests pass.
