Better sorting in library

[Leinnan]

My primary language is polish and I listen to a lot of polish music. Some of the authors have polish characters in name and Sonata isn't sorting them well.
Example of sorting library in Sonata:
Adfasdfas
BASFAafa
Lasfa
Zfsad
ĄGFAS
Łafgas

How it should be:
Adfasdfas
ĄGFAS
BASFAafa
Lasfa
Łafgas
Zfsad

[Mic92]

Probably requires unicode normalisation. I think also python or gtk have some tools on board for locale-aware sorting.