Code Review Request: 7186555: (prefs) continual printing of BackingStoreException on console on Linux

[Kurchi Hazra]

Hi,
  
    Please review this change to fix 718655. The bug complaints about continuous BackingStoreExceptions
printed on the console, the user is just seeing logged warnings from BackingStoreExceptions raised in periodic attempts to sync
preferences. Preferences use sun.util.logging.PlatformLogger.java which is enabled by default, and has a
default level of INFO. Changing the logging in this file to FINE prevents the user from seeing information that he/she is not
interested in.
    
Bug: http://bugs.sun.com/view_bug.do?bug_id=7186555
Webrev:http://cr.openjdk.java.net/~khazra/7186555/webrev.00/

  Thanks,
- Kurchi