functionObject::timeControl: Added runTimes option to execute/write at specified list of run times

With
    executeControl  runTimes;
    executeTimes    (0.1 0.2 0.3);

the functionObject will be executed at 0.1s, 0.2s and 0.3s only.

With
    writeControl    runTimes;
    writeTimes      (0.1 0.2 0.3);

the functionObject will write at 0.1s, 0.2s and 0.3s only.

src/OpenFOAM/db/functionObjects/functionObjectList/functionObjectList.C

@@ -278,7 +278,7 @@ bool Foam::functionObjectList::end()
 }
 
 
-Foam::scalar Foam::functionObjectList::timeToNextWrite()
+Foam::scalar Foam::functionObjectList::timeToNextAction()
 {
     scalar result = vGreat;
 
@@ -291,7 +291,7 @@ Foam::scalar Foam::functionObjectList::timeToNextWrite()
 
         forAll(*this, oi)
         {
-            result = min(result, operator[](oi).timeToNextWrite());
+            result = min(result, operator[](oi).timeToNextAction());
         }
     }