doc: Update Japanese man pages for the description of boot and group handling

Update lxc-autostart(1) and lxc.container.conf(5) for commit 015f0dd.

Signed-off-by: KATOH Yasufumi <karma@jazz.email.ne.jp>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
doc: Fix typo in lxc-autostart(1)

Signed-off-by: KATOH Yasufumi <karma@jazz.email.ne.jp>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>