Deafness, stunning and stuck penalty adjustments

[Coolthulhu]

A couple of balance adjustments:

• Changed deafness to scale instead of just being 100% deafness. Scaling is based on duration and has 3 intensities: reduced hearing volume, further reduced volume and some pain, total deafness and pain (at 300 duration). Noise from small arms will usually only cause the first stage. Added a bit of pain (won't go over 10) when re-applying deafness.
• Nerfed the stunning on hit. Previously it was pretty much guaranteed and scaled well: (bashing+accuracy)/20 turns, capped at 6 turns. This would easily take out a hulk out of combat, provided you get the first strike. Changed to bashing*accuracy > target max hp and capped at 1 turn.
• Removed stuck penalty from impale technique. It is very weak even without it.
• Removed the -20 move penalty on being hit with a knife. Left the second, random, damage-dependent move penalty on being hit with any stabbing weapon. Also didn't remove the -30 move penalty on being hit with a spear (spears are heavy and have low damage, so it fits).
• Changed the dex bonus to attack speed. Before it would plateau around 14 dexterity and be non-random and very reliable. Changed it to a random roll more balanced for both characters with low and high dexterity, not just rewarding the optimal 14.
• Changed stuck penalty halving to one from comment: stuck penalty is halved when the damage is approximately enough to kill the target, instead of just >20.
• Added a strength bonus to countering stuck penalty. 5 move points per point of strength - weaker than skill (~10.5 per skill point), but more reliable.

Also cleaned up some melee combat code.

I'm not sure about the numbers.
I went light on the deafness because 1000 turns of deafness from few burst or 'nades is not OK.
The stuck penalty may be a bit too dependent on strength at lower skill levels.

[Snaaty]

Hm, isnt the deafness effect also added when putting on e.g. noise cancelling headgear? I'd rather not get pain from that.

[i2amroy]

You can chop a zero off of all of your chance numbers here (i.e. "pain_chance": [-5]) and have the nifty side effect of it all moving to a normal percent system there.

[i2amroy]

Hm, isnt the deafness effect also added when putting on e.g. noise cancelling headgear? I'd rather not get pain from that.

Nah, noise canceling headgear is handled separately from the deaf effect right now.

If stacking multiple instances of deafness is the problem with grenades/etc. you might consider just adding a "max_duration": X, flag to it.

Follow up PR idea, make ear plugs only lower noise (similar to a medium level of deafness) rather than making the player totally deaf, since that's generally the way ear plugs work in real life.