Returns HTML for a generic dashboard region.
$variables: An associative array containing:
function theme_dashboard_region($variables) {
extract($variables);
$output = '<div id="' . $element['#dashboard_region'] . '" class="dashboard-region">';
$output .= '<div class="region clearfix">';
$output .= $element['#children'];
// Closing div.region
$output .= '</div>';
// Closing div.dashboard-region
$output .= '</div>';
return $output;
}