tests/check/: Add GST_OPTION_CFLAGS to CFLAGS when building unit tests, so the error...

tests/check/: Add GST_OPTION_CFLAGS to CFLAGS when building unit tests, so the error flags are included and it errors...

Original commit message from CVS:
* tests/check/Makefile.am:
* tests/check/elements/audiopanorama.c: (GST_START_TEST):
* tests/check/elements/videocrop.c: (GST_START_TEST):
* tests/check/elements/videofilter.c:
* tests/check/elements/wavpackdec.c: (GST_START_TEST):
* tests/check/elements/wavpackparse.c: (GST_START_TEST):
Add GST_OPTION_CFLAGS to CFLAGS when building unit tests, so the
error flags are included and it errors out on compiler warnings
for CVS builds; remove unused variables in various unit tests.