Add pipes into stderr and stdout for execute resource
Add pipes into stderr and stdout for execute resource

Squashed commit of the following:

commit 1643459ddb55f15e6eb50e7fd9a9b4fe36aa9e29
Author: Tyler Flint <tylerflint@gmail.com>
Date:   Mon Sep 14 11:08:48 2015 -0600

    converting execute spawn to use open3

pagodabox/hookit,nanobox-io/hookit,nanopack/hookit