gst/schedulers/gstoptimalscheduler.c: Elements without a group can do a state change...

gst/schedulers/gstoptimalscheduler.c: Elements without a group can do a state change as well, just wait with the setu...

Original commit message from CVS:
* gst/schedulers/gstoptimalscheduler.c: (add_to_chain),
(remove_from_chain), (chain_group_set_enabled),
(setup_group_scheduler), (group_element_set_enabled),
(gst_opt_scheduler_state_transition), (gst_opt_scheduler_iterate),
(gst_opt_scheduler_show):
Elements without a group can do a state change as well, just wait
with the setup of the scheduling function when it is added to a
chain.