title: How to plot graph type='h' in ggplot2
body: <p>I'm wondering how to plot in ggplot2 something like this:
  let's say I've got two numeric vectors:
  <code>time &lt;-c(1,3,4,6,9,10,12), n.censor&lt;-c(0,0,1,4,0,3,1)</code>
  and I'd like to plot:
  <code>plot(n.censor~time,type='h')</code></p>
  
  <p>How to achieve something like this in ggplot2 ?</p>