Revised Tony's patch to use a "-r" ("rdata format") command line option instead
of a different command name. Removed the dependency on doc/rfc/rfc5155.txt as a
source of test cases, because the RFC's aren't always packaged with BIND. Changed
the name of the system test from 'nsec3hash' to the more generic 'tools', as we
might want to use it for other things in the future.

Please review rt45183.