Form builder for Symfony login page
<p>How do you create a custom login page built using the form builder and form helper functions to render the view? I finally figured it out! My solution is below.</p>

<p>Why is it needed?</p>

<p>Well I wanted to use the form builder to create the Symfony login page as I wanted to use the form helper functions to render the view. This way my fields would always use the correct template (manually writing the form - as per the Symfony book example - means if the main template was updated the changes to the login form would have to be done manually - and there's a chance of forgetting that!)</p>