Fix #476 Auto language changing function finished.

Fixes issue#476.
If the user does not have the freeseer.conf file, the function will detect the system location for default language.
If there is a config file, the language setting in that file will have higher priority.
For Chinese, If the location is not zh_CN, Traditional Chinese will be used.
If there is no translation for the system location, English will be used.
Regardless if `ja` is correct/incorrect in general, in this case we should be checking for `ja_JP` (Linux) or `ja-JP` (Windows) since it looks like that's what Qt will return.

@Promm can you run the two Python commands I posted above on Windows and show the output?