Update Japanese translation

I suggest some ideas though they are not releated to this Japanese translation.

1. Use Qt 4 to compile for Ubuntu

 Qt5 won't work properly on Ubuntu. Some Japanese characters and QSystemTrayIcon are corrupted on Qt5.
2. Add some dependencies for vitamtp-dev

 It depends on libusb-1.0.0-dev and libxml2-dev
3. Create .gitignore

Thank you for your work!