Add support for field type "password" to WP Settings Framework

wpsf-password-field.php

<?php
switch( $type ){
    case 'text':
        $val = esc_attr(stripslashes($val));
        echo '<input type="text" name="'. $this->option_group .'_settings['. $el_id .']" id="'. $el_id .'" value="'. $val .'" class="regular-text '. $class .'" />';
        if($desc)  echo '<p class="description">'. $desc .'</p>';
        break;
    case 'password':
        $val = esc_attr(stripslashes($val));
        echo '<input type="password" name="'. $this->option_group .'_settings['. $el_id .']" id="'. $el_id .'" value="'. $val .'" class="regular-text '. $class .'" />';
        if($desc)  echo '<p class="description">'. $desc .'</p>';
        break;

...