Fix for scaling issues — A Void Shaper Steam update #435708

Hey, I've worked out a solution for the long existing scaling issues. To be honest: The code I've written is shit, but I've found out a solution to calculate the correct viewport size more precisely. This should finally fix all the scaling issues. Sadly I don't have a monitor that has a bigger resolution than 1080p, but I stretched the game across 3 monitors (side by side) and it's working as expected now (the graphics keep their aspect ratio though). I also improved the player controls a little bit, due to a better method for setting the players position. I hope it works :)!