Clean program in bin/ for deleting junk data or better

[akissz]

Is there a program in ~/roundcube/bin/ that cleans database data from old folder data that is not used anymore? In particular from tables message_threading and search_mods? Or is there a better way? Seems the only way is to manually edit the database, which I can do but that is really weird it is not in core. Just tried to write a plugin to do this but could not get the write data to work correctly so it would not remove the junk from the database, also tried to hook onto the delete folder code and that also did not work. Anybody have something that does this? php or sh script with cron or other method?