Revert a revert of a merge that shouldn't have been in master but was intentionally in staging.
Next time I'll do this right after the revert instead of so far down the line...
This reverts commit 9adad8612b.
This currently only produces a static library, but is a start :) soon we
might be able to incorporate it into our stdenv, but we need to get the
build system to produce a proper .framework first.
