Add a nautilus thumbnailer. Based on patch by Fernando Herrera

2005-03-03  Marco Pesenti Gritti  <marco@gnome.org>

        * Makefile.am:
        * configure.ac:
        * pdf/.cvsignore:
        * pdf/pdf-document.cc:
        * thumbnailer/Makefile.am:
        * thumbnailer/evince-thumbnailer.c: (evince_thumbnail_pngenc_get),
        (main):
        * thumbnailer/evince-thumbnailer.schemas:
        * thumbnailer/pdf-icon.png:

        Add a nautilus thumbnailer.
        Based on patch by Fernando Herrera <fherrera@onirica.com>.