More loose ends of the file copy and paste feature.

	* libnautilus-extensions/nautilus-directory-notify.h:
	Rename NautilusFileChangesQueuePositionSetting to
	NautilusFileChangesQueuePosition. Add a field so it can
	be used to set or remove a position. Rename
	nautilus_directory_schedule_position_setting to
	nautilus_directory_schedule_position_set.

	* libnautilus-extensions/nautilus-directory.c:
	(nautilus_directory_schedule_position_set): Change name and also
	make it handle the case where we want to remove a position rather
	than setting it.

	* libnautilus-extensions/nautilus-file-changes-queue.h:
	* libnautilus-extensions/nautilus-file-changes-queue.c:
	(nautilus_file_changes_queue_schedule_position_set): Name change.
	(nautilus_file_changes_queue_schedule_position_remove): New
	function used to remove a position.
	(position_set_list_free): Name changes, added the new remove
	flavor where needed.
	(nautilus_file_changes_consume_changes): Updated SET case,
	added case for REMOVE.

	* libnautilus-extensions/nautilus-file-operations.c:
	(icon_position_iterator_get_next): New function, used to extract
	the next position out of the iterator.
	(apply_one_position): Simplified by using
	icon_position_iterator_get_next, and also changed so that the
	position is always either removed or set.

	* libnautilus-extensions/nautilus-file-operations.h: Fixed header.

	* libnautilus-extensions/nautilus-gtk-extensions.h:
	* libnautilus-extensions/nautilus-gtk-extensions.c:
	(event_get_time), (nautilus_get_current_event_time): Add new
	function to get the current event time. This is available in GTK
	2.0, so we can remove it when we move up.

	* libnautilus-extensions/nautilus-link.c:
	(nautilus_link_local_create): Updated for change to notify API.

	* libnautilus-extensions/nautilus-program-choosing.c:
	(nautilus_launch_application_from_command): Added FIXME.

	* src/file-manager/fm-directory-view.c: (copy_or_cut_files): Use
	new nautilus_get_current_event_time function. Put up a status
	string about the cut or copy. Since there's no other feedback this
	is especially important.
	(paste_files_callback): Use new nautilus_get_current_event_time
	function.
	(real_selection_clear_event): Erase the status string.
	(real_selection_received): Put up a status string if the paste
	does nothing. Since we can't desensitize the Paste Files command,
	this is the next best thing.