Optimize the case where a component is entirely transparent by skipping

Optimize the case where a component is entirely transparent by skipping

Sun Jan 27 23:58:13 2002  Owen Taylor  <otaylor@redhat.com>

        * pixbuf-render.c (compute_hint): Optimize the case
        where a component is entirely transparent by skipping
        drawing it.

        * pixbuf-rc-style.c (theme_parse_image): Catch case
        where background or overlay border/stretch are specified
        without a background image.

        * pixbuf-render.c (theme_pixbuf_destroy): Actually free
        the structure and filename.