ext/wavpack/gstwavpackdec.*: More clean-ups: remove most of the disfunctional correction pad stuff for now, if it eve...

Original commit message from CVS:
* ext/wavpack/gstwavpackdec.c: (gst_wavpack_dec_base_init),
(gst_wavpack_dec_class_init), (gst_wavpack_dec_init),
(gst_wavpack_dec_finalize), (gst_wavpack_dec_format_samples),
(gst_wavpack_dec_clip_outgoing_buffer), (gst_wavpack_dec_chain),
(gst_wavpack_dec_sink_event), (gst_wavpack_dec_change_state):
* ext/wavpack/gstwavpackdec.h:
More clean-ups: remove most of the disfunctional correction
pad stuff for now, if it ever gets implemented a lot of stuff
will have to be rewritten anyway; redo chain function, move
errors to end, error out instead of g_assert()ing. Also rename
overly long variable 'wavpackdec' to just 'dec'; miscellaneous
other small stuff.