Add vB 3.8.x exporter barebone
Export user groups (vB3)
Export users (vB3)
Export user ranks (vB3)
Export followers (vB3)
Export guestbook entries (vB3)
Export avatars (vB3)
Export conversation labels (vB3)
Export conversations and conversation messages (vB3)
Export conversation users and remove some conversation TODOs (vB3)
Adapt VB38xExporter to 10cf22fea65c3726a2c2a2d8ee64a4ec696dd178
Export boards (vB3)
Export labels (vB3)
Export posts and threads (vB3)

Also fix bug in daysPrune setting
Export watched threads (vB3)
Export polls, poll options and poll option votes (vB3)
Export likes (vB3)
Add code to fixBBCodes() (vB3)
Export attachments (vB3)
Support attachments in filesystem as well (vB3)