Display hidden custom field _values

Adding this snippet to the functions.php of your wordpress theme will allow you to display hidden custom field values. When a custom field value is prefixed within an underscore _value it will not be displayed, using this snippet will display them temporarily.

add_action( 'admin_head', 'showhiddencustomfields' );
function showhiddencustomfields() {
	echo "<style type='text/css'>#postcustom .hidden { display: table-row; }</style>\n";
}