ZE Looting Algorithm

When attacker wins, may loot up to 50% of defender's stock of metal,
crystal, and deuterium.

* Given:

  - Lm :: Amount of lootable metal (50% of defender's stock)
  - Lc :: Amount of lootable crystal (50% of defender's stock)
  - Ld :: Amount of lootable deuterium (50% of defender's stock)
  - C :: Total cargo capacity of attacker's fleet

* Find:

  - Cm :: Carried-away metal amount
  - Cc :: Carried-away crystal amount
  - Cd :: Carried-away deuterium amount
 
* Calculation:

if Lm > C/3
   Cm = C/3
else
   Cm = Lm

if Cm < C/3
   if Lc > (C/2 - Cm)
      Cc = (C/2 - Cm)
   else
      Cc = Lc
else
   if Lc > C/3
      Cc = C/3
   else
      Cc = Lc

if Cm + Cc < 2*C/3
   if Ld > (C - Cm - Cc)
      Cd = (C - Cm - Cc)
   else
      Cd = Ld
else
   if Ld > C/3
      Cd = C/3
   else
      Cd = Ld