Remove @author comments from Drupal

Since the Drupal source code is evolving organically, it is not easy to tell if some source code is written by a particular person or not. CVS blame logs can be investigated (with regard to commit log messages, since commits are proxied), but just marking chunks of code as authored by someone is not our practice. There was one exception. Part of of the locale import system was marked as @author-ed by Jacobo Tarrio, but it was refactored, moved, optimized since then by multiple other developers.

I have explained the above to Jacobo, and he agreed to get his name removed from the source code, to clean up the stage, and create a fair situation. The attached patch removes all @author comments, most of which are about Jacobo, and one of which is about Gerhard. I would expect that Gerhard is not against this change, although I have not asked him for his explicit approval.