Make the generated XML nicely formatted.

modules/atom/libraries/Atom_Base.php

@@ -43,6 +43,7 @@ class Atom_Base_Core {
 
   public function as_xml() {
     $this->add_children_to_base_element();
+    $this->dom->formatOutput = true;
     return $this->dom->saveXML();
   }
 

modules/atom/tests/Atom_Test.php

@@ -24,7 +24,6 @@ class Atom_Test extends Unit_Test_Case {
  * http://codex.gallery2.org/Gallery3:Atom_resource_representations
  *
  * Uncomment one or both lines at the end of the tests to see the output.
- * (You'll have to use your editor to reformat it because there aren't any newlines.)
  */
   public function atom_feed_test() {
     $feed = new Atom_Feed("feed");