Add support for colour stops, equally spaced.

10 stops should be generous!

Add angular linear gradient support!

Add basic support for linear gradients!

Implement background-size!

Fix coordinatespace for texture-pixel lookup.

Build texturing infrastructure & implement background-color!

Build texturing infrastructure.

Add support for background-clip & prepare for multilayered backgrounds!

Fix transformation matrix (should be fixed upstream, but that'd be breaking).

Fix colour output, add OpenGL cleanup.

Add test script!

Implement background-colour rendering!

Draft background-colour shader.