Revert stream base

The introduction of stream_base is a nice idea in itself, but it has not been thoroughly tested and it causes test failures. This is also evidenced by the fact that a ton of followup fixes were necessary which didn't even resolve all the issues. In hindsight it was inappropriate to have landed in on a stable branch.

Therefore I move to revert it, and continue development on the 'NG' branch until it is rock solid.

@indutny cc @bnoordhuis, @rvagg, @mikeal