Diagnosis command to dump config information

[eagle]

From Joe St. Sauver's original suggestion:

This command, when run on a server with INN installed, attempts to determine the version of INN that is installed, the type of spool it is using, the type of overviews it is using, the operating sytem running underneath the whole shebang and anything else that is material and typically required to isolate and diagnose problems when migrating from ancient versions to current version.

innconfval does some of this, but not all of it, and there are some configure-time options that should also be reported. This could just be a flag to innconfval, perhaps.