gst/: Remove the requirement for sub-classes to call the parent implementation of...

gst/: Remove the requirement for sub-classes to call the parent implementation of prepare_output_buffer with a wrappe...

Original commit message from CVS:
* gst/base/gstbasetransform.c: (gst_base_transform_class_init),
(gst_base_transform_prepare_output_buf),
(gst_base_transform_handle_buffer):
* gst/elements/gstcapsfilter.c: (gst_capsfilter_transform_ip),
(gst_capsfilter_prepare_buf):
Remove the requirement for sub-classes to call the parent
implementation of prepare_output_buffer with a wrapper function.

* gst/gsttaglist.h:
* gst/gsttagsetter.h:
Fix #define wrapper