Update dependencies

Required ClosedAdd and ClosedMul for FloatScalar

Avoid accidental trait objects

Implement Blend for blend references

Use a full viewport matrix

Implement Default for Coordinate

Move rasterization code to separate modules

Add method to vertex shader to skip geometry shader stage

Replace rayon with low-level black magic for as little overhead as possible.

Prepare for more texture functionality

Organization

Let the compiler decide what to do for clip methods

Tweak assertions and remove unnecessary casts

Simplify expression

Update image Color implementations to use ColorAlpha