title: Label size in directlabels geom_dl()
body: <p>I have really enjoyed the package <code>directlabels</code> for dynamic positioning the lables of a plot. Although still not perfect, it helps reasonably to prevent overlaps between labels of a scatter plots with many points for example - specially for the draft version of the charts, not the final one. </p>
  
  <p>However I can not find anyway to change the label size while using <code>geom_dl()</code> function. Is there anyway?</p>
  
  <p>I have tried to pass <code>size</code> and <code>cex</code> as a normal or <code>aes()</code> argument to the function.</p>