run/binary: Handle pipes

[mccurdyc]

What would you like to be added:

To be able to handle Unix pipes in the binary external command natively.

Why is this needed:

Links to documentation or design (if any)

https://stackoverflow.com/questions/10781516/how-to-pipe-several-commands-in-go

We could handle this in parsing the external command. Basically anywhere there is a |, create a new exec.Command