NautilusFile.

	* libnautilus-extensions/nautilus-directory-private.h:
	* libnautilus-extensions/nautilus-directory-async.c:
	(metafile_read_close), (nautilus_metafile_read_cancel),
	(metafile_read_failed), (metafile_read_complete),
	(metafile_read_callback), (metafile_read_some),
	(metafile_read_open_callback), (metafile_read_start),
	(nautilus_directory_request_read_metafile), (metafile_write_done),
	(metafile_write_failed), (metafile_write_callback),
	(metafile_write_create_callback), (nautilus_metafile_write_start),
	(metafile_write), (lacks_top_left), (wants_top_left),
	(has_problem), (select_needy_file), (count_lines),
	(top_left_read_done), (top_left_read_failed),
	(top_left_read_complete), (top_left_read_close),
	(top_left_read_callback), (top_left_read_some),
	(top_left_open_callback), (start_getting_top_lefts),
	(state_changed):
	Added code to read top lefts of files in the background.
	Restructured things to accomodate this new code nicely with
	a minimum of copy and paste (there still was plenty of copy
	and paste so there's room for improvement).

	* libnautilus-extensions/nautilus-directory.c:
	(nautilus_directory_destroy):
	Name changes from above required revising some asserts.

	* libnautilus-extensions/nautilus-file-private.h:
	* libnautilus-extensions/nautilus-file.c:
	(nautilus_file_get_top_left_text): Now it returns something
	besides just NULL.
	(nautilus_extract_top_left_text): Function that remembers only
	the part of the top left text that we want to keep around.

	* libnautilus-extensions/nautilus-gtk-extensions.h:
	* libnautilus-extensions/nautilus-gtk-extensions.c:
	(nautilus_gtk_marshal_NONE__POINTER_POINTER_POINTER),
	(nautilus_gtk_marshal_POINTER__POINTER_INT_INT_POINTER_POINTER):
	Needed some new marshal functions.

	* libnautilus-extensions/nautilus-icon-canvas-item.h:
	* libnautilus-extensions/nautilus-icon-canvas-item.c:
	(nautilus_icon_canvas_item_initialize_class),
	(nautilus_icon_canvas_item_destroy),
	(nautilus_icon_canvas_item_set_arg),
	(nautilus_icon_canvas_item_get_arg),
	(nautilus_icon_canvas_item_get_image),
	(nautilus_icon_canvas_item_set_image),
	(nautilus_icon_canvas_item_draw):
	Removed the old embedded text support. It came with a whole lot
	of baggage, also removed.

	* libnautilus-extensions/nautilus-icon-container.h:
	* libnautilus-extensions/nautilus-icon-container.c:
	(nautilus_icon_container_update_icon): Moved pixbuf computing code
	into the FMIconView class. We might decide later to move it back
	again, but for now the embedded text makes it easier to do it
	this way.
	(nautilus_icon_container_initialize_class): Merged
	get_icon_editable_text and get_icon_additional_text back into
	a single signal that gets both.

	* libnautilus-extensions/nautilus-icon-dnd.c:
	(nautilus_icon_dnd_begin_drag): Updated for change in icon factory
	API.

	* src/file-manager/fm-directory-view.c: (finish_loading_uri):
	Ask for top-left text attribute for all directories.

	* src/file-manager/fm-icon-view.c: (get_icon_images_callback):
	Moved pixbuf computing code into the FMIconView class. We might
	decide later to move it back again, but for now the embedded text
	makes it easier to do it this way.
	(get_icon_text_callback): Merged get_icon_editable_text and
	get_icon_additional_text back into a single signal that gets both.