0.5.2

This release introduces 4-player mode.

• Add 4 player support for all game modes (#163)
• Add support for up to 10 joysticks (#65)
• Add option for splitscreen never (#137)
• Add two secret guns (#93)
• Fix crash when changing player appearance (#184)
• Fix second player not having shadows in split screen mode (#164)
• Improve weapon selection menu by disabling selected weapons (#185)
• Improve grenades by using different colours (#171)