Fix prboom port
Created by: xTibor
Depends on #142. This PR fixes the PrBoom port, making it playable: https://youtu.be/-wwwYIqfQik
There are some small issues like the lack of sound or no mouse capture but apart from those it works flawlessly.
Testing:
user:~# /games/prboom -vidmode 32 -iwad something.wad
