ext/wavpack/: More clean-ups: use shorter variable names to make code easier to read...

ext/wavpack/: More clean-ups: use shorter variable names to make code easier to read; prefix structures we define wit...

Original commit message from CVS:
* ext/wavpack/gstwavpackenc.c: (gst_wavpack_enc_init),
(gst_wavpack_enc_finalize), (gst_wavpack_enc_sink_set_caps),
(gst_wavpack_enc_set_wp_config), (gst_wavpack_enc_format_samples),
(gst_wavpack_enc_push_block), (gst_wavpack_enc_chain),
(gst_wavpack_enc_rewrite_first_block),
(gst_wavpack_enc_sink_event), (gst_wavpack_enc_change_state),
(gst_wavpack_enc_set_property), (gst_wavpack_enc_get_property):
* ext/wavpack/gstwavpackenc.h:
* ext/wavpack/gstwavpackparse.c: (gst_wavpack_parse_reset),
(gst_wavpack_parse_src_query), (gst_wavpack_parse_src_event),
(gst_wavpack_parse_init), (gst_wavpack_parse_get_upstream_length),
(gst_wavpack_parse_loop):
More clean-ups: use shorter variable names to make code easier to
read; prefix structures we define with 'Gst' to make it clearer
where they come from.