because it confuses gtk-doc and breaks some links. Also change the
"Index of new symbols in GIMP 2.x" sections to be what seems to be the
modern standard (looked at the GLib and GTK+ docs), and update some
other stuff.
Change gimp_pixbuf_create_buffer() to copy the pixels if a linear
buffer cannot be created. Add functions that convert between
GimpTempBuf and GdkPixbuf. Fix users of gimp_pixbuf_create_buffer()
to make the least possible copies. Patch modified by Mitch.