Podem me mostrar alguma maneira de fazer upload de logo através do Pai

Estou trabalhando no desenvolvimento de um theme wordpress do zero e estou colocando uma página de "Theme Settings" nesse theme, para alterar coisas como a logo, links de ícones, copyright etc.

Para fazer o Painel segui esse tutorial: http://wpmidia.com.br/tutoriais/tutorial-wordpress-como-criar-abas-em-sua-theme-options-page

Preciso de um código HTML para colocar no Theme Settings em que eu possa fazer o upload de uma imagem, e armazenar no wordpress para que seja usada como logo.

Meu código está assim:

Arquivo adminsettings.php

<?php

add_action( 'init', 'wptester_admin_init' );
add_action( 'admin_menu', 'wptester_settings_page_init' );

function wptester_admin_init() {
	$settings = get_option( "wptester_theme_settings" );
	if ( empty( $settings ) ) {
 $settings = array(
 'wptester_intro' => 'Some intro text for the home page',
 'wptester_tag_class' => false,
 'wptester_ga' => false
 );
 add_option( "wptester_theme_settings", $settings, '', 'yes' );
	}
}

function wptester_settings_page_init() {
	$theme_data = get_theme_data( TEMPLATEPATH . '/style.css' );
	$settings_page = add_theme_page( $theme_data['Name']. ' Theme Settings', $theme_data['Name']. ' Theme Settings', 'edit_theme_options', 'theme-settings', 'wptester_settings_page' );
	add_action( "load-{$settings_page}", 'wptester_load_settings_page' );
}

function wptester_load_settings_page() {
	if ( $_POST["wptester-settings-submit"] == 'Y' ) {
 check_admin_referer( "wptester-settings-page" );
 wptester_save_theme_settings();
 $url_parameters = isset($_GET['tab'])? 'updated=true&tab='.$_GET['tab'] : 'updated=true';
 wp_redirect(admin_url('themes.php?page=theme-settings&'.$url_parameters));
 exit;
	}
}

function wptester_save_theme_settings() {
	global $pagenow;
	$settings = get_option( "wptester_theme_settings" );

	if ( $pagenow == 'themes.php' && $_GET['page'] == 'theme-settings' ){
 if ( isset ( $_GET['tab'] ) )
 $tab = $_GET['tab'];
 else
 $tab = 'homepage';

 switch ( $tab ){
 case 'general' :
 $settings['wptester_tag_class'] = $_POST['wptester_tag_class'];
 break;
 case 'footer' :
 $settings['wptester_ga'] = $_POST['wptester_ga'];
 break;
 case 'homepage' :
 $settings['wptester_intro'] = $_POST['wptester_intro'];
 break;
 }
	}

	if( !current_user_can( 'unfiltered_html' ) ){
 if ( $settings['wptester_ga'] )
 $settings['wptester_ga'] = stripslashes( esc_textarea( wp_filter_post_kses( $settings['wptester_ga'] ) ) );
 if ( $settings['wptester_intro'] )
 $settings['wptester_intro'] = stripslashes( esc_textarea( wp_filter_post_kses( $settings['wptester_intro'] ) ) );
	}

	$updated = update_option( "wptester_theme_settings", $settings );
}

function wptester_admin_tabs( $current = 'homepage' ) {
 $tabs = array( 'homepage' => 'Home', 'general' => 'General', 'footer' => 'Footer' );
 $links = array();
 echo '<div id="icon-themes" class="icon32"><br></div>';
 echo '<h2 class="nav-tab-wrapper">';
 foreach( $tabs as $tab => $name ){
 $class = ( $tab == $current ) ? ' nav-tab-active' : '';
 echo "<a class='nav-tab$class' href='?page=theme-settings&tab=$tab'>$name</a>";

 }
 echo '</h2>';
}

function wptester_settings_page() {
	global $pagenow;
	$settings = get_option( "wptester_theme_settings" );
	$theme_data = get_theme_data( TEMPLATEPATH . '/style.css' );
	?>

	<div class="wrap">
 <h2>Theme Settings</h2>

 <?php
 if ( 'true' == esc_attr( $_GET['updated'] ) ) echo '<div class="updated" ><p>Theme Settings updated.</p></div>';

 if ( isset ( $_GET['tab'] ) ) wptester_admin_tabs($_GET['tab']); else wptester_admin_tabs('homepage');
 ?>

 <div id="poststuff">
 <form method="post" action="<?php admin_url( 'themes.php?page=theme-settings' ); ?>">
 <?php
 wp_nonce_field( "wptester-settings-page" );

 if ( $pagenow == 'themes.php' && $_GET['page'] == 'theme-settings' ){

 if ( isset ( $_GET['tab'] ) ) $tab = $_GET['tab'];
 else $tab = 'homepage';

 echo '<table class="form-table">';
 switch ( $tab ){
 case 'general' :
 ?>
 <tr>
 <th><label for="wptester_tag_class">Tags with CSS classes:</label></th>
 <td>
 <input id="wptester_tag_class" name="wptester_tag_class" type="checkbox" <?php if ( $settings["wptester_tag_class"] ) echo 'checked="checked"'; ?> value="true" />
 <span class="description">Output each post tag with a specific CSS class using its slug.</span>
 </td>
 </tr>
 <?php
 break;
 case 'footer' :
 ?>
 <tr>
 <th><label for="wptester_ga">Insert tracking code</label></th>
 <td>
 <textarea id="wptester_ga" name="wptester_ga" cols="60" rows="5"><?php echo esc_html( stripslashes( $settings["wptester_ga"] ) ); ?></textarea><br/>
 <span class="description">Enter your Google Analytics tracking code</span>
 </td>
 </tr>
 <?php
 break;
 case 'homepage' :
 ?>
 <tr>
 <th><label for="wptester_intro">Text Logo</label></th>
 <td>
 <textarea id="wptester_intro" name="wptester_intro" cols="60" rows="5" ><?php echo esc_html( stripslashes( $settings["wptester_intro"] ) ); ?></textarea><br/>
 <span class="description">Digite o texto que irá aparecer na área da logo:</span>
 </td>
 </tr>
 <?php
 break;
 }
 echo '</table>';
 }
 ?>
 <p class="submit" style="clear: both;">
 <input type="submit" name="Submit" class="button-primary" value="Update Settings" />
 <input type="hidden" name="wptester-settings-submit" value="Y" />
 </p>
 </form>

 </div>

	</div>
<?php
}

Arquivo functions.php

<?php
/ WIDGETS /

if (function_exists('register_sidebar'))
{
register_sidebar(array(
'name' => 'Sidebar',

 'before_widget'	=> '<div class="widget">',
 'after_widget'	=> '</div>',
 'before_title'	=> '<h3>',
 'after_title'	=> '</h3>',
 ));
}

register_nav_menu( 'main-menu', 'Menu Principal' );

/ Load up our theme options page and related code. /

if ( is_admin() ) require_once( TEMPLATEPATH . '/adminsettings.php' );

?>

Arquivo header.php [sAÍDA DAS INFORMAÇÕES DIGITADAS NO PAINEL DE ADMIN]

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" xmlns:og="http://opengraphprotocol.org/schema/" xmlns:fb="http://www.facebook.com/2008/fbml">
<head>
<title><?php wp_title(''); ?></title>

<meta http-equiv="Content-Type" content="<?php bloginfo('html_type'); ?>; charset=<?php bloginfo('charset'); ?>" />
<meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0">

<link rel="profile" href="[http://gmpg.org/xfn/11](http://gmpg.org/xfn/11)" />
<link rel="stylesheet" type="text/css" media="all" href="<?php bloginfo( 'stylesheet_url' ); ?>" />
<link href="css/bootstrap.min.css" rel="stylesheet" media="screen">
<link rel="pingback" href="<?php bloginfo( 'pingback_url' ); ?>" />

<?php if ( is_singular() && get_option( 'thread_comments' ) ) wp_enqueue_script( 'comment-reply' ); wp_head(); ?>

</head>

<body>
	<header id="header-geral">
 <div class="container">
 <a href="./index.php"><?php $opcoes = get_option('wptester_theme_settings'); echo $opcoes['wptester_intro']; ?></a>

 <nav>
 <?php wp_nav_menu( array( 'location'=>'main-menu', 'container'=>'div', 'container-class'=>'menu', 'menu_class'=>'ul-menu' ) ); ?>
 </nav>
 </div>

	</header>

Agradeço a atenção e a ajuda.