Added note about new Unicode version.

activesupport/CHANGELOG.md

@@ -16,6 +16,8 @@
 *    BufferedLogger is deprecated.  Use ActiveSupport::Logger, or the logger
      from Ruby stdlib.
 
+*    Unicode database updated to 6.1.0.
+
 ## Rails 3.2.0 (January 20, 2012) ##
 
 *   Add ActiveSupport::Cache::NullStore for use in development and testing. *Brian Durand*