[PR] Gravity and Gravity Tethers

[glowbold]

Rebalance Focused on High-G:
* Internal: Convert all floats to ints all my homies hate floats
* Balance: Being submerged in fluid neutralizes per-tick impacts of high gravity
* Balance: Being submerged in fluid gives you full traction
* Balance: Jetpacks prevent low-G stamina sapping for humans
* Balance: Super-extreme-G interferes with human sight.
* Balance: High cap on per-tick damage (previously uncapped)
* Balance: Fitness machines scale stamina buffs based on Gs directly instead of a differing bonus at different gravity thresholds
* Balance: Floating atoms resist high-G
* Balance: The "Space Movement" equipment property has been converted to "Zero-G Movement" and works in all zero-G environments

[Mikeistaken]

I think the station wide tether should have the amount of materials needed reduced

Reason for request:
Miners generally cant get Quill consistently and most people don't know that Erebite works as extraordinarily dense crystal, lowering this number will allow for another gravity tether to be made, especially when the miners get their full equipment and decide to go to some random place