don't use BUILT_SOURCES as its broken in automake 1.4, add explicit object

don't use BUILT_SOURCES as its broken in automake 1.4, add explicit object

Wed Sep 19 02:50:40 2001  Tim Janik  <timj@gtk.org>

        * demos/Makefile.am ($(testpixbuf_OBJECTS)): don't use BUILT_SOURCES
        as its broken in automake 1.4, add explicit object rule to
        generate this.

        * gdk-pixbuf/Makefile.am: fix maintainer and normal cleanfiles.
        get rid of uneccessary stamps, group stuff more logically, and build
        sources due to object rules. fix srcdir!=builddir.