title: ggplot legends - change labels, order and title
body: <p>I'm struggling a great deal to modify the legend in my plot. Here is a reproducible example:</p>
  
  <pre><code>dtt &lt;- structure(list(model = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L), .Label = c("ma", "mb", "mc"), class = "factor"), year = c(2005L, 2006L, 2007L, 2008L, 2009L, 2010L, 2005L, 2006L, 2007L, 2008L, 2009L, 2010L, 2005L, 2006L, 2007L, 2008L, 2009L, 2010L), V = c(0.16, 0.14, 0.11, 0.13, 0.15, 0.16, 0.24, 0.17, 0.12, 0.13, 0.15, 0.15, 0.2, 0.16, 0.11, 0.12, 0.12, 0.15), lower = c(0.11, 0.11, 0.07, 0.09, 0.11, 0.12, 0.16, 0.12, 0.04, 0.09, 0.09, 0.11, 0.14, 0.1, 0.07, 0.08, 0.05, 0.1), upper = c(0.21, 0.19, 0.17, 0.17, 0.19, 0.2, 0.29, 0.23, 0.16, 0.17, 0.16, 0.2, 0.26, 0.27, 0.15, 0.16, 0.15, 0.19)), .Names = c("model", "year", "V", "lower", "upper"), class = "data.frame", row.names = c(NA, -18L))
  </code></pre>
  
  <p>My plot is generated like this:</p>
  
  <pre><code>ggplot(dtt, aes(x=year, y=V, group = model, colour = model, ymin = lower, ymax = upper)) +
      geom_ribbon(alpha = 0.35, linetype=0)+ 
      geom_line(aes(linetype=model), size = 1.5) +       
      geom_point(aes(shape=model), fill = "white", size = 4)  +      
      theme(legend.position=c(.6,0.8)) +
      theme(legend.background = element_rect(colour = 'black', fill = 'grey90', size = 1, linetype='solid'))
  </code></pre>
  
  <p>which produces this:
  <img src="https://i.stack.imgur.com/xTgJi.png" alt="enter image description here"></p>
  
  <p>Now, what I would like to do is</p>
  
  <ol>
  <li>change the title of the legend</li>
  <li>change the order in which the legend items appear</li>
  <li>change the text of the legend items.</li>
  </ol>
  
  <p>I have fiddled around for hours trying to do this, but without much success. The best I have managed so far is to add this:</p>
  
  <pre><code>scale_colour_hue(name = "Model 1",
      breaks=c("mb", "ma", "mc"),
      labels=c("MBB", "MAA", "MCC"))
  </code></pre>
  
  <p>But it produces this abomination:
  <img src="https://i.stack.imgur.com/je9Bi.png" alt="enter image description here"></p>
  
  <p>As you see, there is now an extra unneeded legend, and the shapes in the legend do not match those in the plot !</p>
  
  <p>Finally, I would like to graphics in the legend to indicate that the blue and green lines are dashed, not solid - but I have no idea at all how to do that.</p>
  
  <p>Any assistance would be highly appreciated,</p>