replace submit as "YOURSELF" with submit as "Username"

Issue Summary

Hi,

I know that you are busy with bugfixes, but I thought this would be a small little improvement to have especially since people on my site have expressed a confusion over "Submit as" feature.

Right now the Submit As form presents the choice of "YOURSELF" and "the username of the Artificial user". I think it would make a lot more sense and be more intuitive if the word "YOURSELF" in that form was automatically replaced by the actual username of the person who is submitting that content.

So if user Mickey is submitting a scoop, it would be better to trace his name and write Submit As: "Mickey" rather than "YOURSELF".
Just a small little feature request to make Drigg neater.

Thanks