Updated Polish translation
Use GError in FLAC tagging code

Avoid several uses of Log_Print().
Use GError in APE tagging code

Avoid a use of Log_Print().
Use GError in ID3 tagging code

Avoid several uses of Log_Print(), and convert some more into warnings
or debugging messages.
Use GError in MP4 tagging code

Avoid several uses of Log_Print().
Use GError in Ogg header code

Avoid a few Log_Print() calls.