#2251 Added CActiveRecord::generateMetaData method, modified getMetaData() method to avoid recursion (Grigori Kochanov)
placed the changelog comment in the right order
Update CActiveRecord.php

fixed getMetaData() : instead of passing a string it needs to pass the model object to CActiveRecordMetaData
Update CActiveRecord.php

Added the private $_mdCache property to serve the requests for metadata objects from a cache.
#10 Updated CActiveRecord. Removed the infinite loop, added the MetaData object cache.