feat: balance weapon damage

[jdrueckert]

This is an attempt to balance the weapons a bit better.
We do have different dimensions along which we can assess the (combat) value of a weapon:

• range
• damage
• ammo requirements
• cooldown

Weapon	Range	Ammo?	Damage	Cooldown	Time to Kill	(Combat) Value
Sword	2	no	20-30	500	2000	?
Waraxe	2	no	40-60	1000	2000	?
Staff (Melee)	2	no	?	?	?	?
Staff (Fireball)	long	infinite	10	300	3000	?
Spear (Melee)	4	no	20-30	1000	4000	?
Spear (Throw)	long	yes (self)	100	100 (slot change)	100	?
Crossbow (Arrows)	long	finite	20	200	1000	?

(Time to kill is ceil(playerMaxHealth / damage) * cooldown with playerMaxHealth = 100)

Melee weapons - sword, axe (, staff, spear)

• Con: need to get close to enemy
• Pro: acceptable to high damage

Ranged, ammo-less weapons - staff (fireball)

• Con: low damage, hard to hit opponent
• Pro: endless ammo, acceptable cooldown, long range

Ranged, ammo-requiring weapons - Crossbow (arrows)

• Con: requires ammo, hard to hit opponent
• Pro: low cool down, acceptable damage, long range

Ranged, pick-up weapons - Spear (throw)

• Con: needs to be picked up, hard to hit opponent
• Pro: very high damage, long range

How can we estimate a reasonable (combat) value based on these properties?
Based on the formula we come up with, I'd like to derive the monetary value of the items.

[jdrueckert]

Superseded by Terasology/LightAndShadow#249