Teal 13 05 acu81706 incorporate process watcher as popen3 sync

@ryanwilliamson the big popen merge. In a nutshell, moved legacy RightScale.popen3 to RightScale::RightPopen.popen3_async (uses eventmachine) and introduced RightScale::RightPopen.sync to fully replace the deprecated process_watcher gem. added a little more spec coverage but the full spec suite is still distributed over at least six different projects (right_popen, right_scraper, mixlib-shellout, ohai, chef, right_link). Creates a slot for mingw to fit into but still not implemented.