[client] po: Consistent Japanese notations.

- If the word with 3 or more vowels ends with prolonged sound,
  omit the last "-".
- Use Japanese period.

Signed-off-by: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com>
Merge pull request #569 from project-hatohol/messages-20140917a

[client] po: Consistent Japanese notations.