Allow rendering other modules from placeholders

[TarLaboratories]

What

Adds new placeholders:

• {module <slot> <x> <y>}
  Renders the specified module on the central monitor (i.e. if there's an image module in the slot it renders the image)
• {setImage <slot> <url>}
  Sets the URL in an image module
• {rect <x> <y> <width> <height> <color>}
  Renders a rectangle with the specified parameters
• {quad <x1> <y1> <x2> <y2> <x3> <y3> <x4> <y4> <color1> <color2> <color3> <color4>}
  Renders a quad with the specified parameters

Outcome

Images can be rendered dynamically with placeholders. Also adds API to allow placeholders to render anything basically.

This feature only works for the central monitor. Any additional rendering from placeholder won't be called in the cover renderer.

Screenshots

Stale