Updated Japanese locale
correct a translation error.
work on the options
correct another tranlation mistyping
..
...
I believe now the background-position is working :)
?????
:)
:)
Revert ":)"

This reverts commit 7727eb125f3e967b8932b2fa53fd845842c78672.
background position seems ready.
update the languages from the older version (3.6)
1. Fix a bug, that if the customized background image is not available (for example, deleted), the options dialog won't show up.
2. When there is no customized background image, the related buttons will be 'disabled'.
3. Change the version to 4.6.0.