ptimized version of method for adding multiple nodes to atlas.
Uses less of the atlas' area (it sorts images by the size before adding them to atlas).</p><p class="javadoc">Parameters:</p><table class="table table-bordered params"><tr><th style="width:25%;"><code>bitmaps</code></th><td><p><code><a href="../../../openfl/display/BitmapData.html#BitmapData">BitmapData</a></code>'s to insert</p></td></tr><tr><th style="width:25%;"><code>keys</code></th><td><p>Names of these <code><a href="../../../openfl/displa