* Remove ZLEVEL_STATION_PRIMARY
* Add Up and Down traits for use by ladders and chasms
* Give map_config creation its own proc
* Combine LoadConfig and ValidateJSON and remove transition_config
* Make space linkage a z-level trait
* Remove ZLEVEL_EMPTY_SPACE
* Update uses of GetFullMapPath
* Handle multi-Z stations and load Lavaland and Reebe at runtime
* Remove unused space maps
* Fix inappropriate z-expansion in map reader, improve logging
* Update comments relating to z-level configuration
* Add Lavaland and Reebe to ALL_MAPS
* Add basic structure of z-level traits
* Restore space transitions and add z-level debug verb
* Restore proper ruin spawning and transit level creation
* Replace station_z_levels and related checks with traits
* Eliminate more uses of ZLEVEL_{STATION_PRIMARY,LAVALAND}
