ENH: ignore -noFunctionObjects option when disabled

- With argList::noFunctionObjects() we use the logic added in
  4b93333292 (issue #352)

  By removing the '-noFunctionObjects' option, we automatically
  suppress the creation of function-objects via Time (with argList
  as a parameter).
  There is generally no need in these cases for an additional

      runTime.functionObjects().off()  statement

  Use the argList::noFunctionObjects() for more direct configuration
  and reduce unnecessary clutter in the -help information.

  In previous versions, the -noFunctionObjects would have been redundant
  anyhow, so we can also just ignore it now instead.

applications/utilities/mesh/generation/snappyHexMesh/snappyHexMesh.C

@@ -710,9 +710,10 @@ int main(int argc, char *argv[])
     #include "addProfilingOption.H"
     #include "addDictOption.H"
 
+    argList::noFunctionObjects();  // Never use function objects
+
     #include "setRootCase.H"
     #include "createTime.H"
-    runTime.functionObjects().off();
 
     const bool overwrite = args.found("overwrite");
     const bool checkGeometry = args.found("checkGeometry");