CXX-265 Configure logging through startup options

A few comments/questions:

-For cleanup of appenders, there's a clearAppenders() function, and this will actually delete the appenders.  Though it seems clear that when you attach the appender you hand ownership of it over to the log domain, users using these options won't see that call, and I wonder if they'd be surprised by this behavior.  Also, since we're not using the appender handles at all, or allowing the user to use them, I wasn't sure how important it was to call clearAppenders() at all.

-Where should configureLoggingOptions() live?  Options.cpp seems like an ok option, but I think there's probably a better fit.  If I add a cleanup function that should probably live in the same place.

-Should there be a way to configure, through options, specific minimum logged severity levels for different logging domains?  If you were doing it manually, you'd be able to set it by component.
BTW I like that you included the auto_ptr in the return type of the factory function signature. You didn't need to do it that way (it could have returned a bare EventAppender* and would have worked fine), but by requiring the return type of the users function to be an auto_ptr it sends a clear message to the author of a function intended to be used with this interface that ownership of the returned object is being taken over by the library.