title: Method available for connecting pairs of circles in RaphaelJS 2?
body: <p>In plain <code>svg</code>, the <code>&lt;line&gt;</code> tag seems to do that just fine, e.g.</p>
  
  <pre><code>&lt;g&gt;
      &lt;line class="link" x1="180" y1="280" x2="560" y2="280"&gt;&lt;/line&gt;
  &lt;/g&gt;
  &lt;g&gt;
      &lt;circle class="node" cx="180" cy="280" id="n1" r="18"&gt;&lt;/circle&gt;
      &lt;circle class="node" cx="560" cy="280" id="n2" r="18"&gt;&lt;/circle&gt;
  &lt;/g&gt;
  </code></pre>
  
  <p>Here, the <code>line</code> element draws a line connecting the two defined nodes.</p>
  
  <p>In <code>RaphaelJS 2</code>, is there a method for doing this? It seems like the most likely one is <code>path</code>, but when I try:</p>
  
  <pre><code>var paper = Raphael(document.getElementById("raphael-test"), 600, 600);
  var c1 = paper.circle(180, 280, 18);
  var c2 = paper.circle(560, 280, 18);
  var edge = paper.path("M180,280L560,280");
  </code></pre>
  
  <p>the line <em>extends into</em> both circles, reaching the center of the circle. Visually I would like the line to just touch the line of circle. Of course, I can just work out the geometry and subtract the radius of the circle for each end given the pair coordinates. But I wonder if some method is already available from <code>RaphaelJS 2</code>, as this seems to be a very common functionality.</p>