title: Go up one command instead of one line in IPython 5
body: <p>IPython 5 is a big release. One of its features is real multi-line editing with prompt_toolkit. The up arrow key now moves to the previous input line instead of the previous input command (block of lines).</p>
  
  <p>This is awesome, but when my previous command spans many lines, and I need to reach the command before that, I find myself wishing I could go up one command at a time. Is there a way to do that? The shortcut <kbd>ctrl</kbd><kbd>p</kbd> has the exact same behaviour as the up arrow key, so it does not provide a solution.</p>