Fix typos and mistranslations:
o ip6fw.8 (add missing punctuations, remove a garbage line, and

add missing .An -nosplit line)

o isdnd.8 (fix wrong translation in the last sentense in EXAMPLES)
o jail.8 (fix wrong transltation related to empty /etc/fstab description)
o kldunload.8 (SYNOPSIS was not same as original)
o lpc.8 (use correct Japanese wording)

Submitted by: Satoru Koizumi <koizumi@cms.phys.s.u-tokyo.ac.jp>