title: Polymer Paper-Radio-Group - how to have multiple radio buttons with the same name
body: <p>I'm using Paper Elements from the Polymer Project to build a form, and have run into a problem using the <code>paper-radio-group</code> tag and its children, <code>paper-radio-button</code>.  With a normal radio button list, I would do the following:</p>
  
  <pre><code>&lt;input type="radio" name="myFieldName" value="MyFirstOption" /&gt;
  &lt;input type="radio" name="myFieldName" value="MySecondOption" /&gt;
  &lt;input type="radio" name="myFieldName" value="MyThirdOption" /&gt;
  </code></pre>
  
  <p>Note that the <code>name</code> attributes are the same, grouping the radio buttons and producing a single value for the <code>myFieldName</code> field.  However using the <code>paper-radio-group</code> element in the same way does not work:</p>
  
  <pre><code>&lt;paper-radio-group label="My Field"&gt;
    &lt;paper-radio-button name="myFieldName" label="First"&gt;&lt;/paper-radio-button&gt;
    &lt;paper-radio-button name="myFieldName" label="Second"&gt;&lt;/paper-radio-button&gt;
    &lt;paper-radio-button name="myFieldName" label="Third"&gt;&lt;/paper-radio-button&gt;
  &lt;/paper-radio-group&gt;
  </code></pre>
  
  <p>This produces three radio buttons, but selecting one doesn't deselect the others.  If I give each a unique name then it works from a UI perspective, but is different than the standard radio button behaviour.</p>
  
  <p>In addition to this, where do I specify the value for each radio button?  There is a label property, but nothing for value.  Am I going to have to wire up a hidden field to the <code>change</code> event of the <code>paper-radio-button</code>, or the <code>core-select</code> event on the <code>paper-radio-group</code>?  Neither seems like a particularly elegant solution.</p>