Merge "16x16 DCT blocks." into experimental

configure

test/dct16x16_test.cc

test/fdct8x8_test.cc

test/idct8x8_test.cc

test/test.mk

vp8/common/alloccommon.c

vp8/common/blockd.h

vp8/common/coefupdateprobs.h

vp8/common/default_coef_probs.h

vp8/common/entropy.c

vp8/common/entropy.h

vp8/common/entropymode.c

vp8/common/generic/systemdependent.c

vp8/common/idct.h

vp8/common/idctllm.c

vp8/common/invtrans.c

vp8/common/invtrans.h

vp8/common/loopfilter.c

vp8/common/onyxc_int.h

vp8/decoder/decodframe.c