Fixed drop rule not to use --reject-with

 * --sleep option added
 * --bytemarkdns-dir option documented
 * --template option better documented
 * The hash checksum file will not be written if upload fails.

chains, and the jumps to them, when they're disabled, in case they're
re-enabled later.

done by the symbiosis-create-* scripts

routines.

nothing has been specified by the do_exim4_bt caller.

the advertised manner.