Fixes and interface improvements

• Fix: players are no longer left without a weapon after dropping the equipped item and healing with a medkit.
• Fix: equipped items no longer swap mysteriously after drinking an energy drink
• Tweak: healing with medkits from inventory works better, makes smarter choices of medkits
• Fix: loot from dead enemies is now always identical for all co-op players
• Fix: Purna no longer finishes her Fury with fists equipped
• Fix: map tracking after death
• Fix: zone info in the quarantine zone (City of Moresby)
• Tweak: respawn point selection is now smarter