Bug 974589 - [contacts] Contacts needs open activity to support text/vca...

...rd because bug 887663 added it to the MimeMapper so email thinks they are downloadable
I would suggest this improvement to the rendering algorithm

```js
var firstContactRendered = false;
if(contact) {
  if(!firstContact) {
    firstContact = contact;
  }
  else if(!firstContactRendered) {
    render(firstContact);
    render(contact);
    firstContactRendered = true;
  }
  else {
    renderContact();
  }
  cursor.continue();
}
else if(firstContact) {
  renderOne();
}
```