Merge changes I7d6394e4,Ia8ce1464,If20e8637,Ia9adc46b,I651db25b into nextgenv2

* changes:
  Define SIMD_INLINE using AOM_FORCE_INLINE
  AOM_FORCE_INLINE: fix always_inline attribute
  Free memory allocated by daala_ec encoder.
  Move clpf_sse4_1.c to clpf_sse4.c in agreement with convention
  sync avg_test.cc with aom/master