m_spanningtree Squit dead servers immediately when they die, not at the next timer tick
m_spanningtree Throw a ProtocolException if a server SQUITs a server it shouldn't
Allow fast sid reuse by erasing fake users from UserManager::uuidlist when the netsplit is handled, not in cull()
Do not attempt to detect non-culled users at destruction by looking for their uuid, leave it to Extensible

This does not take uuid/sid reuse into consideration and Extensible implements this detection already in a proper way