Reimplement some of the gl-matrix methods

[stasm]

For instance, mat4.create could be implemented as:

return Float32Array.of(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1);

[stasm]

There are also quite a few bytes that we could shave off by making our own methods return results instead of writing to the first argument. Once the core code stabilizes I'll make an inventory of the methods we use and I'll try to reimplement them.

[michalbe]

@stasm is this still a valid issue? We've tried that last week, without any reasonable lean boost.

[stasm]

Rolling a custom implementation of matrix math is a big task. gl-matrix does the job well and has a better testing coverage. I vote close.