Investigate options for emscripten blas generators and node-only solutions

[kyonifer]

For the js side, we may end up needing two backends: one for node (which calls out to optimized blas, see e.g. Vectorious) and one for everything else (browser, etc). One route that might enable us to get the "everything else" bin implementing all of our ops could be the automatic emscripten blas generators that are out there.