ENH: improve handling of noFunctionObjects / withFunctionObjects (issue #352)

- do not enable function objects by default if there is no means of
  disabling them.

src/OpenFOAM/db/Time/Time.C

@@ -515,7 +515,9 @@ Foam::Time::Time
         *this,
         argList::validOptions.found("withFunctionObjects")
       ? args.optionFound("withFunctionObjects")
-      : !args.optionFound("noFunctionObjects")
+      : argList::validOptions.found("noFunctionObjects")
+      ? !args.optionFound("noFunctionObjects")
+      : false
     )
 {
     libs_.open(controlDict_, "libs");
@@ -590,7 +592,6 @@ Foam::Time::Time
 {
     libs_.open(controlDict_, "libs");
 
-
     // Explicitly set read flags on objectRegistry so anything constructed
     // from it reads as well (e.g. fvSolution).
     readOpt() = IOobject::MUST_READ_IF_MODIFIED;