Rework stages/platforms

[rukai]

Stages/platforms are currently very simple.

More features are needed including:

• wall and ceiling collisions on platforms
• angled platforms
• moving platforms

In order to achieve these they will likely need to be completely reworked.

[rukai]

Moving platforms shouldnt be touched until we have scripting.

Platforms were reworked to include angled platforms. Still need to add wall and ceiling collisions.