title: country-labels on spplot()
body: <p>I'd like to add name-labels for regions on an spplot().</p>
  
  <p>Example:</p>
  
  <pre><code>load(url('http://gadm.org/data/rda/FRA_adm0.RData'))
  FR &lt;- gadm
  FR &lt;- spChFIDs(FR, paste("FR", rownames(FR), sep = "_"))
  load(url('http://gadm.org/data/rda/CHE_adm0.RData'))
  SW &lt;- gadm
  SW &lt;- spChFIDs(SW, paste("SW", rownames(SW), sep = "_"))
  load(url('http://gadm.org/data/rda/DEU_adm0.RData'))
  GE &lt;- gadm
  GE &lt;- spChFIDs(GE, paste("GE", rownames(GE), sep = "_"))
  
  df &lt;- rbind(FR, SW, GE)
  
  ## working
  plot(df)
  text(getSpPPolygonsLabptSlots(df), labels = c("FR", "SW", "GE"))
  
  
  ## not working
  spplot(df[1-2,])
  text((getSpPPolygonsLabptSlots(df), labels = c("FR", "SW"))
  </code></pre>
  
  <p>The second one probably doesn't work because of lattice!?
  However, I need the spplot-functionality.
  How would I get the labels on the plot?</p>