Fixed missing Japanese characters in the OSK.

ie see Issue #2386 https://github.com/hrydgard/ppsspp/issues/2386
Also added the vowel lengthening character to Katakana and Hirigana

Before:
![](https://f.cloud.github.com/assets/4050814/686705/5c2dd430-da62-11e2-87e4-083c7e1ab154.png)

After:
![](https://f.cloud.github.com/assets/712067/705591/6e21427e-ddd9-11e2-8e61-172775095d16.png)

Ended up being garbled because they were the incorrect encoding in the file.