Rewrite a bit: use GstBaseSink::start and stop instead of a state change function; use GST_ELEMENT_ERROR for error re...

Original commit message from CVS:
* ext/shout2/gstshout2.c: (gst_shout2send_base_init),
(gst_shout2send_class_init), (gst_shout2send_init),
(set_shout_metadata), (gst_shout2send_set_metadata),
(gst_shout2send_event), (gst_shout2send_start),
(gst_shout2send_connect), (gst_shout2send_stop),
(gst_shout2send_render), (gst_shout2send_set_property),
(gst_shout2send_get_property), (gst_shout2send_setcaps),
(plugin_init):
* ext/shout2/gstshout2.h:
* po/POTFILES.in:
Rewrite a bit: use GstBaseSink::start and stop instead of a state
change function; use GST_ELEMENT_ERROR for error reporting, not
g_error() or GST_ERROR(); don't unref caps in setcaps function,
will cause crashes or assertion failures; remove (unused) "sync"
property, basesink already has such a property; misc. other
minor fixes and cleanups.