Options: (default value in parenthesis)
	-c class (IN)
	-d directory
	directory to find signedkey files (.)
	-s YYYYMMDDHHMMSS|+offset:
	SIG start time - absolute|offset (now)
	-e YYYYMMDDHHMMSS|+offset|"now"+offset]:
	SIG end time  - absolute|from start|from now (now + 30 days)
	-i interval:
	cycle interval - resign if < interval from end ( (end-start)/4 )
	-v debuglevel (0)
	-o origin:
	zone origin (name of zonefile)
	-f outfile:
	file the signed zone is written in (zonefile + .signed)
	-r randomdev:
	a file containing random data
	-a:     verify generated signatures
	-p:     use pseudorandom data (faster but less secure)
	-t:     print statistics
	-n ncpus (number of cpus present)
	Signing Keys: (default: all zone keys that have private keys)
	keyfile (Kname+alg+tag)
	See draft-ietf-dnsext-keyrr-key-signing-flag-00.txt for the details on how to distinguish between the two types of keys.