Added some mozc improvements for FreeBSD:
- add signal treatments for FreeBSD to do correct
termination process (remove socket file and lock file
as closing time).
- improve socket filename treatment
Now mozc_server does correct termination process. By this
improvements, you don't need mozc-additions anymore. But
commands included in mozc-additions is safe and useful for
start, stop, restart and launch mozc tools even now.