Upgrade dns/dnsdbq to 2.5.1:

• add zone times to datefix, add json to reverse, fix usage messages
• remove some name-reversal debugging output; handle names which don"t end in dots
• add "truncate" transform, clean up the "reverse" string arithmetic
• Add missing trailing period and newline to the -8 usage text
• retire APIKEY from the environment, allow it only in config file
• remember when the system has been specified
• change transform "truncate" to be called "chomp"
• portability fixes

Sponsored by: Farsight Security, Inc.