Copyright notice

[Chris Shoemaker]

Devs,
        We should should update the copyright notice in the "About"
dialog to be current and more accurate.  It should indicate that
copyright for GnuCash is held by various people.

        Current suggestions are:

1.  (C) 1998-2006, Contributors
2.  (C) 1998-2006, the GnuCash developers
3.  (C) 1998-2006, GnuCash contributors
3.  (C) 1998-2006, (see AUTHORS file)
4.  Listing individual names and years for major contributors in the
past few years.

        From the discussions so far, there don't seem to be strong
feelings on the matter.  If you have a strong preference for a
particular phrase, speak up now.  Otherwise, I will go with #3 before
2.0 is shipped.

-chris