Version 1.1 almost done (Windows, Mac, Linux)

So first. Thanks for your patience. My latest project have been taking up all my available time :)

V1.1 almost done. Features:

- Updated Unity version.
- Updated Mirror version (network library)
- Updated network transport to support uPnP (more on this later)
- Fixed bugs related to updating libraries.
- Allowed GPU instancing for materials that supported it (performance).
- Added more advanced network interpolation, for smoother gameplay.
- Bullet holes, now follows a door, when you open/close it :)
- You can now play over the internet with an uPnP router. 
(Note! You need to accept firewall dialog on game start.
If your firewall does not support uPnP or you can't get it to work, 
forward UDP port 7777 in your router, to your host PC <- Only if hosting)
- Now also Mac and Linux clients (untested, so please give feedback)
- No more installer. Just a zip file :)