First batch of work for bug 4875 (design for running arbitrary
	scripts on selected items). Only works locally, doesn't notice
	changes to scripts directory, doesn't pass selected items as
	parameters, many other details unfinished.

	* src/file-manager/nautilus-directory-view-ui.xml: Add "Run Script"
	submenus to File and context menus; add missing tip I happened to
	notice to Open With submenu.

	* src/file-manager/fm-directory-view.c:
	(script_launch_parameters_new), (script_launch_parameters_free):
	New helper functions to manage lifetime of parameters for script
	menu items.
	(get_scripts_directory): New function, returns NautilusDirectory
	object (or NULL) representing scripts directory.
	(fm_directory_view_initialize): Remember scripts directory in
	details struct.
	(fm_directory_view_destroy): clean up scripts directory stuff.
	(add_numbered_menu_item): renamed from add_open_with_program_menu_item
	with no other changes, since it was already exactly general enough
	for my new use.
	(add_application_to_bonobo_menu), (add_component_to_bonobo_menu):
	Update for name change.
	(change_to_view_directory): New function to change working
	directory to the one displayed.
	(run_script_callback): New function to actually execute the script;
	temporarily changes the working directory.
	(add_script_to_menus): New function, adds one script to the two
	Run Script menus.
	(reset_scripts_menu): New function, fills in the two Run Script
	menus from scratch.
	(reset_scripts_menu_callback): New call_when_ready callback, calls
	reset_scripts_menu.
	(disconnect_script_handlers): New function, cleans up pending callbacks.
	(schedule_reset_scripts_menu): New function, sets up a callback when
	the files in the scripts directory are sufficiently known.
	(real_merge_menus): Call schedule_reset_scripts_menu.


	Fixed bug 7232 (vague error message and console spam when
	refreshing a directory deleted outside of Nautilus)

	* src/file-manager/fm-error-reporting.c:
	(fm_report_error_loading_directory): Handle the NOT_FOUND
	case explicitly.