Fix translation truncation in matrix edit widget

![badmatrixedit](https://f.cloud.github.com/assets/83110/2070945/3db83d60-8d22-11e3-9271-6bb24b879b04.png)

Translation in matrix edit widget are forcefully truncated to 17 bytes, resulting in bad UTF-8 string. Attached picture shows comparison between Japanese and English glyph info UI.