Missing info from upgrade instructions

Hi guys, great framework, you do a great job!

Just wanted to inform you of a problem we had…

Check-in r2278 added serialization/deserialization to cookie values. It meant that any old cookies were invalidated. This gave a poor user experience to our existing users, but we only realised after going live with the Yii upgrade… because there was no mention of this change in the upgrade instructions or release notes :o

Please can you be really over cautious when decided what to mention in the upgrade instructions… thanks :)