Fix some old import problems where I used 'from django.contrib import auth' instead of 'from django.contrib.auth.models import User'. Also some formatting changes while I was in there.

div.potd-details {
    text-align: center;
}
div.potd-details p.caption {
    font-weight: bold;
}
div.potd-details p.details {
    font-style: italic;
    font-size: smaller;
}