Fixed subtitle/osd memory leaks (subpicture_region_t->psz_text was not freed).
I think we have a potential bug with the way subpicture_region_t->p_style is used. Decoders allocate p_style memory in their context, so we don't free it in spu_DestroyRegion. As vout object can live longer than decoder, I think p_style might be used after the decoder has destroyed it. Can someone, who has worked on osd/spu internal, comment ?