Major refactor of organize:

* Clean up naming conventions for variables in the controller
  so that we specifically refer to albums with $album_id, etc.

* Move complexity for drawing tree out of the controller and into
  the view.

* Simplify task definitions to get rid of extraneous text

* Change __PLACEHOLDERS__ to clearly define which is the album
  and which is the item that we're moving before/after

* Remove as many CSS ids as we can from the tree view to keep
  things simple

modules/organize/views/organize_thumb_grid.html.php

@@ -1,5 +1,5 @@
 <?php defined("SYSPATH") or die("No direct script access.") ?>
-<? foreach ($item->children(25, $offset) as $child): ?>
+<? foreach ($album->children(25, $offset) as $child): ?>
 <li class="gMicroThumbGridCell" ref="<?= $child->id ?>">
   <div id="gMicroThumb_<?= $child->id ?>"
        class="gMicroThumb <?= $child->is_album() ? "gAlbum" : "gPhoto" ?>">
@@ -8,10 +8,10 @@
 </li>
 <? endforeach ?>
 
-<? if ($item->children_count() > $offset): ?>
+<? if ($album->children_count() > $offset): ?>
 <script>
   setTimeout(function() {
-    $.get("<?= url::site("organize/content/$item->id/" . ($offset + 25)) ?>",
+    $.get("<?= url::site("organize/content/$album->id/" . ($offset + 25)) ?>",
       function(data) {
         $("#gMicroThumbGrid").append(data);
         $.organize.set_handlers();