Adds z-level hearing / speaking

[FreeStylaLT]

About The Pull Request

Also comes with arrows to indicate verticality for chatlogs:

At the moment every NON-WHISPER message can travel upwards / downwards.

LIMITATIONS:

• If the speaker has a ceiling above them, you won't be able to hear them.
• If you are below someone and you have a ceiling above you, you won't be able to hear someone above.
• Also vice-versa (you are above someone, and they have a ceiling)
• Basically it only works across the open turfs.
• Though not 100% sure, but I think being on the top z-level won't let you be heard by someone under you.

CONCERNS:
This adds more garbage to say code that is used hundreds if not thousands of times every round. I recommend a TM.

Incredibly massive thanks to @charore on Discord for basically single-handedly finding the underlying bug that was preventing this functionality.

Why It's Good For The Game

Real eavesdropping!! Can you believe it!
Might be tied to perception / sneak skill or something later, if this is deemed stable / mergeable.