pingo. Rename render object to render geometry.
ludus/pingo. Changes to create render geometry.

Render geometry no longer owns shader variables.
Shader variables are passed as C pointer to render geometry construction, and are never deleted.
The game will own the shader variables, and can store them directly, or as part of game object data.
The game will destroy the shader variables in its own destruction, or when game object data is destroyed.
This change includes the required changes in both the pingo and ludus libraries.