gst/base/gstbasesink.c: Make sure the GstFlowReturn is returned.

gst/base/gstbasesink.c: Make sure the GstFlowReturn is returned.

Original commit message from CVS:
* gst/base/gstbasesink.c: (gst_base_sink_handle_object):
Make sure the GstFlowReturn is returned.

* gst/gstbus.c: (gst_bus_add_signal_watch_full),
(gst_bus_add_signal_watch):
* gst/gstbus.h:
add gst_bus_add_signal_watch_full.

* gst/gstplugin.c: (gst_plugin_load_file):
Small style cleanup.