Accurate Stamina Display

Fixes the stamina meter display on the HUD, so it more accurately represents your current stamina percentage.

In the original game, the meter appears full until you are at about 90% stamina, and it appears empty when you still have about 20% stamina left.

Includes several configurable settings:

• Keep the "empty at 20%" behavior, since some players are accustomed to using it as an indicator to not release the sprint key.
• Display the entire meter, but change its color to red when you can't sprint, so you know how much time is left until you can sprint again.
• Always display the last 20% of the meter in red, a sort of hybrid approach that offers information from both of the above settings.
• Gradually change the meter's base color to indicate "endurance" from TZP-inhalant. (orange -> yellow -> green -> white)