Merge remote branch 'qatar/master'

* qatar/master:
  aacdec: Use float instead of int16_t for ltp_state to avoid needless rounding.
  acelp: Remove unused gray_decode table.
  dfa: Remove unused variable.
  configure: Include AVX availability in summary output.
  configure: use same CPPFLAGS in kFreeBSD as Linux

Merged-by: Michael Niedermayer <michaelni@gmx.at>

diff --cc configure
Simple merge

diff --cc libavcodec/aac.h
Simple merge

diff --cc libavcodec/aacdec.c
Simple merge

diff --cc libavcodec/acelp_vectors.c
Simple merge