message: Update to c++14
diff: @@ -159,8 +159,8 @@ function(set_common_target_properties TARGET)
  POSITION_INDEPENDENT_CODE ON
  # It is crucial to set CXX_STANDARD flag to only affect c++ files and avoid failures compiling c-files:
  - # error: invalid argument '-std=c++11' not allowed with 'C/ObjC'
  - CXX_STANDARD 11
  + # error: invalid argument '-std=c++14' not allowed with 'C/ObjC'
  + CXX_STANDARD 14
  CXX_STANDARD_REQUIRED ON
  C_STANDARD 11
  