[Infected:RE] Structure Changes.

Some building structure changes. Added one more weapon shop at the isolated house. I understand nobody cares about the attic of the little house, so let's rebuild it to make it more worthy of a defence point.

Also added another stair that connects the dining hall with the second floor. The dining hall was designed as one of the open-spaced defence points, but its long distance to any ammo supply and limited exit made it a terrible spot. Hopefully, this change fix that issue for it.

As I noticed many players find difficulty grabbing the weapon dropped from the loot box, I changed the loot box reward to be floating in mid-air for easier access. 

These changes along with some bug patches will be delivered later tonight. (Morning for US time.)