Player stamina system

[Matthew Cain]

Base stamina value calculation formula:

• hunger_value + thirst_value = stamina_value
• e.g. 30/50 hunger + 45/50 thirst = 75/100 stamina

Stamina should be further reduced by the following factors:

• Environmental damage.
• Damage from enemy attacks.
• Running and walking.
• Interacting with environment.

Stamina value will have a direct impact on player movement speed and attack damage.
Less then 25% stamina will half the players movement speed and physical attack damage.

[Deleted user]

Change: make player de-buffs more gradual in relation to reduced stamina.