Agent now inherits group

Do not use agent.gfx anymore.
Bug fixed agent's eye follow

Moved bird functions to prototype, because: why not?
Bird hero objects hack & /

Tweens should not start automatically, otherwise they cannot be chained.
Change times to duration, way easier to use.
Only tint appropriate parts.
A lot of documentation.
Updates to agent
Correct order for minigame disabler
Renamed minigames to subgames

This is to reflect the terminology that is used when talking about the
game. "Minigame" felt incorrect since these games are what makes up the
game.
Filename changes