Stepping down from doceng@.

Mark and Hiroki are doing good jobs as new member, so I can pass
all my (especially Japanese/localization specific) doceng hats
to Hiroki and other doceng members.

I'll focus to use my FreeBSD time for activities in other area
(like core, *master, ...).

And I hope I can find time to do actual translation works, not
management nor engineering works. :-)