Replace Subprocess::pipe* syntax sugar with Subprocess::Options().pipe*

Replace Subprocess::pipe* syntax sugar with Subprocess::Options().pipe*

Summary:
This is a bit too magical -- it's not clear that the thing produces an Options object. If you do know that you can chain further option setters off this thing, it's nice, but otherwise, the first impression is "what just happened?".

So, let's have one good way for doing things.

Reviewed By: yfeldblum

Differential Revision: D4863947

fbshipit-source-id: 3dfe83cfc077d47f604f47dcb21149fbaa2d2243