Make AjaxFlexibleFileUpload serializable

[paulhoadley]

This pull request makes AjaxFlexibleFileUpload serializable, and is a fix for #653.

[darkv]

This will change the reported class name for those using the logger and having subclassed the AjaxFlexibleFileUpload. But making that logger static makes sense to me.

[paulhoadley]

Yes, what you say is true, but there's no way around it: if the field is static, we can't call getClass() in it's initialisation. I'd argue that the more important issue is that the class advertises Serializable, but, as written, it's not serializable. (Of course, I'm arguing that precisely because I want to serialize it and can't!)

What about if I advertise the change on the list and see if this would affect anyone in the way you describe?

[darkv]

Or merge this and put a note on the next release notes about that change?

[paulhoadley]

I'm happy to do both. (I'd be surprised if it affected anyone at all.) I'll post now, you can merge this in 24-48 hours if there's no feedback.

[darkv]

Fine :-)

[paulhoadley]

No response on the list in 36 hours...