Minor patch 2

Small patch. Unless I manage to turn all enemies into fleshrats by introducing inverted Y axis I will now take a small break, due to having the flu.

• Added option to invert mouse Y axis.
• Added option to limit FPS
• Fixed a money exploit.
• Menu frontend should now more accurately represent actual settings after booting the game.

If you're having problems with the resolution and text size, you should try disabling Windows UI scaling for this game.