I actually want blocking semantics!

I made a small modification to remove the nonblock flags and calls from the darwin and linux.

I was writing a simple protocol that does line back and forward, and didn't want to spend a bunch of effort on flow control.

Instead of that I just removed the non-blocking behavior so that I could easily stall on write and read at an appropriate rate.

Totally happy if this doesn't fit your use case and you just want to close out.