Update README.md
server bug fix
added block_history table in server
added cleanup helper to server, looks for blocks in db that match the default world block and can be safely deleted
no vacuum
fix
no need to cache chunks in cleanup
don't count pad blocks
cleanup indestructibles too
added config.py to .gitignore (local server config)
Update README.md
moved static globals in main.c into a Model struct
removed some Model members
fix
added helper functions
proper cleanup
added /online, /offline commands - can switch in-game
updated reset_model
added server help for /online /offline commands
updated readme