Finished bug 2146 (Properties window for desktop Trash
	should show Trash properties). The last two changes were
	to remove the "accessed" field for all directories, since
	it seems useless, and to fill in the "where" field with
	"on the desktop".

	* libnautilus-extensions/nautilus-file.c:
	(nautilus_file_get_where_string): New function, calls
	virtual function so trash and normal files can report
	different strings.
	(nautilus_file_get_string_attribute): Changed "parent_uri"
	string attribute to "where", since it is not the parent_uri
	in the Trash case.
	* libnautilus-extensions/nautilus-file.h: Virtual function
	pointer for get_where_string.
	* libnautilus-extensions/nautilus-trash-file.c:
	(trash_file_get_where_string),
	(nautilus_trash_file_initialize_class): Supply get_where_string
	function that returns "on the desktop".
	* libnautilus-extensions/nautilus-vfs-file.c:
	(vfs_file_get_where_string), (nautilus_vfs_file_initialize_class):
	Supply get_where_string function that returns parent_uri string.
	* src/file-manager/fm-properties-window.c:
	(should_show_accessed_date): New function, returns FALSE for
	directories and TRUE for other files.
	(create_basic_page): Honor should_show_accessed_date, and use
	"where" instead of "parent_uri" string attribute.
	* src/file-manager/fm-search-list-view.c:
	(real_get_column_specification): Use "where" instead of "parent_uri"
	string attribute.