The purpose of this crate is to make it a bit more ergonomic for portable
applications that need to work with the platform level RawFd and
RawHandle types.
Rather than conditionally using RawFd and RawHandle, the FileDescriptor
type can be used to manage ownership, duplicate, read and write.
The Pipe type makes it more convenient to create a pipe and manage
the lifetime of both the read and write ends of that pipe.