add tinyMCE to category and tag description

[zabatonni]

clients often asks how to add hyperlink or bold text into category description.

simple solution is to edit core wp-admin/edit-tag.php
and replace line 65 with this code

<?php wp_editor(html_entity_decode($tag->description),'description',array('wpautop'=>true,'media_buttons'=>false,'quicktags'=>true,'textarea_rows'=>'15','textarea_name'=>'description')); ?>

but it's always getting back after updating

[SergeyBiryukov]

Duplicate of #20901.

Also, no need to hack the core file, there's a plugin for that:
​http://wordpress.org/extend/plugins/rich-text-tags/