Laser turret in progress

New content:

- Laser turret added to the game. The .gif shows how the 3 types look like after the 10th and the 20th level ups (currently the damage is scaled up so the level ups are near instantenious).

Bug fixes:

- Armor factory selection now does not change when the player changes ammo type to produce.

- Gatling gun's ammo shell droppings particle system fixed, so it does not come out of the barrel.