- Attaching to rtorrent doesn't work right (rtorrent stops accepting input)
  (The problem is that rtorrent is using epoll to poll stdin, and we don't
   update the internal reference that the epoll fd has to the old tty).

- Attaching to a process with children doesn't work right.
  This should be possible to fix -- I just need to ptrace each child
  individually and do the same games to it.
