Revert "Merge pull request #125 from brainopia/master"

It appears that this is causing issues with process termination.

This reverts commit d2c9ce0f34, reversing
changes made to 98337c92e1.

lib/foreman/process.rb

@@ -30,13 +30,11 @@ private
   def fork_with_io(command)
     reader, writer = IO.pipe
     pid = fork do
-      Process.setpgrp
       trap("INT", "IGNORE")
       $stdout.reopen writer
       reader.close
       exec Foreman.runner, replace_command_env(command)
     end
-    Process.detach pid
     [ reader, pid ]
   end