842310a9b0
Caminandes team request. In current master it's not possible to do this in a total clean way, so we are simply setting all user counts of given lib's datablocks to zero (similar to rna_ID_user_clear()'s doing). This is a bit crappy because it still lets datablocks floating around (with invalid user count values), and requires a save & reload cycle to be finalized. But for now it should be good enough. Propper implementation will be added to id-remap.