Fix bugs 2943 (Dragging icons between windows or to the desktop
	triggers scrolling), 4786 (Need to remove tree view auto-expand
	feature for 1.0) and 4476 (weird horizontal autoscroll
	behavior). Auto-scroll now has a consistent 750 ms startup delay,
	and the tree auto-expand is off.

	* libnautilus-extensions/nautilus-drag.h,
	libnautilus-extensions/nautilus-drag.c:
	(nautilus_drag_autoscroll_in_scroll_region,
	nautilus_drag_autoscroll_start, nautilus_drag_autoscroll_stop):
	New convenience functions that factor out common code formerly in
	the tree, list and icon view DnD code. This fixes the mistakes
	common to all three of those views, where the auto-scroll initial
	delay was measured from the start of dragging overall, not from
	entering the scroll region.

	* libnautilus-extensions/nautilus-icon-private.h,
	libnautilus-extensions/nautilus-icon-dnd.c
	(auto_scroll_timeout_callback, set_up_auto_scroll_if_needed,
	stop_auto_scroll): Use the above calls. Also, correct a `<'
	vs. `>' mistake that made the auto-scroll delay never take effect.

	* libnautilus-extensions/nautilus-list.c
	(auto_scroll_timeout_callback, nautilus_list_start_auto_scroll,
	nautilus_list_stop_auto_scroll): Use the above calls. Also,
	correct a `<' vs. `>' mistake that made the auto-scroll delay
	never take effect.

	* components/tree/nautilus-tree-view-dnd.c:
	(nautilus_tree_view_drag_leave, nautilus_tree_view_drag_motion,
	collapse_time_callback, nautilus_tree_view_expand_node,
	nautilus_tree_view_is_tree_node_expanded, nautilus_dump_info
	expand_hack_unref, expand_hack_new, expand_time_callback,
	nautilus_tree_view_expand_maybe_later): Remove bunches of code to
	disable auto-expand.

	(ready_to_start_scrolling, auto_scroll_timeout_callback),
	(nautilus_tree_view_start_auto_scroll),
	(nautilus_tree_view_stop_auto_scroll),
	(nautilus_tree_view_drag_destroy): Use new common auto-scroll
	code. I also made it possible to add an extra auto-scroll delay
	for horizontal auto-scroll, but now that the startup delay has
	been fixed, it seems almost impossible to trigger horizontal
	auto-scroll accidentally, so I consider 4476 fixed.

	* components/adapter/bonobo-stream-vfs.c: (vfs_get_info,
	vfs_set_info, vfs_write, vfs_read, vfs_copy_to, vfs_destroy,
	bonobo_stream_vfs_open): Added FIXME bug numbers.
	* components/adapter/nautilus-adapter-control-embed-strategy.c:
	(activate_uri_callback): Added FIXME bug numbers.
	* components/adapter/nautilus-adapter.c: (nautilus_adapter_new):
	Added FIXME bug numbers.