facets: case and accent insensitive sort

[Sébastien Lamy]

Hi!

When I ask solr for facets, with the parameter "facet.sort=index", it 
gives me the facets sorted alphabetically, but case and accent sensitive.

I found no way to have the facets returned with the original case and 
accents, and sorted alphabetically, with no sensibility to case and accents.

Is there anything I can do to achieve this goal, without having to 
retrieve all facets and sort it myself? (We have fields with many, many 
facets, and doing so impacts performance a lot).

Sebastien.