Ported 'see-down' open spaces from Vore, who ported it from Eris
Ported talking and visible messages traveling upwards through open spaces
Tested, seems to work? Does not seem to break anything, maybe.
Maybe made a changelog.
* Don't infinately accumulate underlays!
* Ease up on the New() and Destroy(), make sure they are a top level object (loc is a turf)
* The open space darkness overlay is always the same, make it a global.
* New atom to hold a turf's decal overlays instead of the turf itself.
* Change floor_decal initialization to use it instead, and change other decal/overlay interaction procs to use it instead.
* Add floor decal initialization to master controller to do them in one fel swoop instead of nickel and diming.
* Stop area init from updating open space turfs; let the open space controller do it.
* Instead of open spaces simply showing a static image of the turf below, it shows the turf, all objects, and even moving mobs.
* Controller updates the view to floor below fairly quickly; mobs update in real time.
* Open space can be examined to see how deep it is.
* Mobs are examinable even when on floor below, using a special "zshadow" mob.
* Changes from Eris: Heavily re-written to handle layering, special cases, rewrote controller etc. Shadow mobs don't break entering turfs, etc.
* Update to properly layer the objects from multiple "below" floors in the case of tripple-stacked or more z levels.
* Added constant defines for the planes in use.
* Added open_space.dmi with blank_open icon state for open space's darkening overlay.
* Port of https://github.com/Baystation12/Baystation12/pull/16942
* Actually tell turfs when a thrown object hits them, and let them decide what to do about it!
* We do this by calling hitby(), which is how it already works for obj and mob, so this makes behavior consistent.
* This allows us to cleanly solve the problem of a thrown object landing on open space without falling.
* Global procs should start with /proc
* Use to_chat() macro
* Added utility to find all z-levels are connected (transitively adjacent) and utility to test if two levels are connected.
More tweaks to IPC fixes.
Merge resolution/compile fixes.
Further work on properly integrating, updating and fixing prosthetic options.
Repathed internal organs to organ/internal.
More work on full synthetics, changelings, overheating.
Working on getting organs to qdel properly and spawn properly when robotized.
Finalized some overheating values, added remaining prosthetic icons.
Finalizing the testing version of the full prosthetic bodies branch.
Added suit cyclers to the autolathe and map.
Fixing runtime errors.
Fixing errors.
Changelog.
Replacing limb and organ strings with constants.
Prevented brainless species from becoming full cyborgs.
Fixed issues with brain/MMIs renaming themselves inappropriately.
Various fixes and oversights.
