Support for the taxonomy_fields module

It would be nice if this module supported taxonomy_fields. I've spent half a day trying to get it working, but because both modules do funny stuff and have certain expectations, I can't get it working.

At the very least, this patch has no side effects and makes the form alterable:

@@ -888,7 +889,8 @@ function taxonomy_manager_tree_build_siblings_form($tree_id, $page

_taxonomy_manager_tree_sub_forms_set_parents($tree_id, $parent, $siblings_form);

- $siblings_form = form_builder('taxonomy_manager_form', $siblings_form, $form_state)
+ drupal_prepare_form('taxonomy_manager_form', $siblings_form);

$output = drupal_render($siblings_form);