Add projectiles and ranged weapons.

[dpc]

The basic UI for aiming is implemented, but other things are missing.

[dpc]

I've added a Bow, that can shoot.

Bugs/missing:

• It's possible to shoot through walls
• it's possible to shoot things not in LoS
• range does not mater
• there are no separate stats for ranged weapons
• bow being two handed weapon, should block left hand item slot