v0.4 Hats! (and more)

Hey all! I added hats today. Yes, hats add a lot to the game. You can wear them and stuff. Anyhow, still working on this game in my free time!

- Added 6 hats

- Leaders in FFA gamemode now wear a crown

- Improved gamesettings screen open animation

- Slightly reduced respawn invincibility time

- Special bar is now more obvious when filled

- Progress of special bar is now more visible when not filled

- Made 3, 2, 1, countdown last slightly less long

- Fixed where you couldn't skip player introduction after stage introduction finished

- Fixed where invincibility shader wouldn't account for team color

- Fixed where game wouldn't start when someone left but everyone else was already ready.

- Box Factory particles are larger and spread more

- Improved invincibility shader

- Changed color of blue background to be a bit lighter

- PlayerIconUI & StaticPlayerIconUI now derive from BasePlayerIconUI