title: Ember Interpolation in a href tag in handlebars template
body: <p>I am trying to make a simple link to google maps with a dynamic address inserted into the href field. I have tried the code below plus tons of other messing around with no luck. How do you interpolate a dynamic ember string in a handlebars href field?</p>
  
  <p>I am using ember,rails, and handlebars.
  I know how to use bindAttr if I had the entire url stored with my model but I only have the address. Putting the google url with every model seemed unnecessary if i could just call it once in the view.</p>
  
  <pre><code>&lt;h1&gt;{{name}}&lt;/h1&gt;
   &lt;div&gt;
    &lt;p&gt;&lt;a {{bindAttr href='http://maps.com/?1=address'}}&gt;{{address}}&lt;/a&gt;&lt;/p&gt;
   &lt;/div&gt;
  
  &lt;h1&gt;{{name}}&lt;/h1&gt;
  &lt;div&gt;
    &lt;p&gt;&lt;a href='http://maps.google.com/?q={{address}}'&gt;{{address}}&lt;/a&gt;&lt;/p&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>What I used to Fix it</p>
  
  <pre><code>App.Location = DS.Model.extend(
    name: DS.attr('string', defaultValue: "")
    address:  DS.attr('string', defaultValue: "")
    fullAddress: (-&gt;
      "http://maps.google.com/?q=#{@get('address')}"
    ).property('address')
  )
  </code></pre>