edit_category_form action adjustment

[johnkolbert]

In categories.php an action on line 281 called "edit_category_form" allows plugins to add information to the category form. However, this action runs AFTER the submit button for the form and isn't very useful as is.

To make this action useful I purpose moving line 281 up two lines so that it runs BEFORE the submit button is created on the screen. This allows plugin authors to add category form elements which appear before the submit button.

updated categories.php

updated file using the categories.php from version 2.8-beta2-11456. Lines affected are 285-287

dup of #8831 and #2717