message: doxygen: drop deprecated TCL_SUBST
diff: @@ -39,7 +39,6 @@ ALIASES += end_toggle="@htmlonly[block] </div> @endhtmlonly"
  ALIASES += prev_tutorial{1}="**Prev Tutorial:** \ref \1 \n"
  ALIASES += next_tutorial{1}="**Next Tutorial:** \ref \1 \n"
  ALIASES += youtube{1}="@htmlonly[block]<div align='center'><iframe title='Video' width='560' height='349' src='https://www.youtube.com/embed/\1?rel=0' frameborder='0' align='middle' allowfullscreen></iframe></div>@endhtmlonly"
  -TCL_SUBST =
  OPTIMIZE_OUTPUT_FOR_C = NO
  OPTIMIZE_OUTPUT_JAVA = NO
  OPTIMIZE_FOR_FORTRAN = NO
  