changelog: Document scoring difference for Important flag

* Treat the Important flag like the Essential flag with those differences:
  - No higher score for installation ordering

debian/changelog

@@ -42,9 +42,10 @@ apt (0.8.16~exp13) UNRELEASED; urgency=low
     - Set the Essential flag on APT instead of only Important
   * apt-pkg/packagemanager.cc:
     - Do not use immediate configuration for packages with the Important flag
-  * Treat the Important flag like the Essential flag with two differences:
+  * Treat the Important flag like the Essential flag with those differences:
     - No Immediate configuration (see above)
     - Not automatically installed during dist-upgrade
+    - No higher score for installation ordering
 
  -- David Kalnischkies <kalnischkies@gmail.com>  Mon, 30 Jan 2012 19:17:09 +0100