fixed bug 4369, throbber frozen during long refresh, by making the
	throbber a bonobo component so it's driven by its own thread.
	Note that clicking on the throbber is temporarily broken; I'll
	fix that soon.  Also, made the frame delay be specified by the
	theme and set the default to spin somewhat slower than before.

	* configure.in:
	* components/Makefile.am:
	* components/throbber/.cvsignore:
	* components/throbber/Makefile.am:
	* components/throbber/nautilus-throbber.oafinfo:
	added throbber component

	* components/throbber/main.c: (throbber_object_destroyed),
	(throbber_make_object), (main):
	factory for the throbber component

	* components/throbber/nautilus-throbber.c,h:
	(nautilus_throbber_initialize_class), (is_throbbing),
	(get_bonobo_properties), (set_bonobo_properties),
	(nautilus_throbber_destroy), (nautilus_throbber_get_control),
	(get_throbber_dimensions), (nautilus_throbber_initialize),
	(nautilus_throbber_new), (naut...