[Usability] gpdf UI review

[=?utf-8?b?UsOpbWkgQ29oZW4tU2NhbGk=?= <Remi Cohen-Scali com>]

Hy all

I am working on adding gpdf with news outlines navigation features 
(bookmarks, thumbnails, annotations, signatures).
I choose a galeon like sidebar design for presenting these views to the 
user.
Some screenshot previews are availables here:
http://www.rcsnet.net/freeware.html#gpdf

Please let me know your thoughts about it as I'am in a very early stage 
and can still change everything.

Thanks