When we receive a distributed notification, any objects added to the autorelease...

When we receive a distributed notification, any objects added to the autorelease pool won't be released until the next time the program is sent an NSEvent, it appears.  We therefore should use a manual autorelease pool around the observer methods to prevent build-up of any autoreleased memory. This fixes a problem in which memory usage would build up over time when an autoupdating status message was in use and Adium was left alone for a long period of time. Fixes #8892

git-svn-id: svn://svn.adiumx.com/adium/trunk@22526 1c916fce-81e2-0310-a464-8ca513f45935