Include portable libfaust installation with package

[Smona]

Having to install libfaust separately isn't ideal. It would be better to bundle a portable version of libfaust either in the package contents, or during a postinstall hook.

I had a go at doing this, but the current implementation of running the faust compiler in wasm (libfaust-wasm + wasm-wrapper) doesn't work in nodejs because node doesn't support preloaded memory. C++ really isn't my strong suit, so the current means of calling the compiler is pretty hacky and could be improved on.

Related Faust issue: grame-cncm/faust#598