Merge pull request #12 from nejc92/master

warship model (doesn't work)
Merge pull request #4 from Rgti2013/master

Sync from main
Merge pull request #13 from nejc92/master

cannons fixed
Merge pull request #14 from nejc92/master

linear velocity fix
Merge pull request #5 from Rgti2013/master

Sync from main
Game logic, GUI

- added basic win conditions
- added GUI
- TODO: fix a large bug with respawn, ship gets super slow
Merge pull request #15 from okacat/master

Basic game logic, GUI
Merge pull request #8 from Rgti2013/master

Game logic, GUI