• Fill with empty chunks before loading to avoid starlight
• Fix race condition that could cause blank chunks

Credit to chunked-pl's fork for most of the following changes

• Only prime FULL heightmaps
• Remove autosave task from map when cancelled
• Cache block->string and string->block conversions
• Reduce memory used by light arrays
• Fix /polar rename
• Fix loadworld only reporting error to console, not command caller
• Fix saving outside worlds folder in rename, createfromregion, convert, createblank and paste
• Fix world userdata removed on save (fixes schematics losing center point)