STYLE: changes to Time and TimeState

- update TimeState access methods

- use writeTime() instead of old method name outputTime()

- use deltaTValue() instead of deltaT().value()
  to avoids pointless construct of intermediate

src/dynamicFaMesh/interfaceTrackingFvMesh/functionObjects/writeFreeSurface/writeFreeSurface.C

@@ -48,7 +48,7 @@ namespace Foam
 
 bool Foam::writeFreeSurface::writeData()
 {
-    if (time_.outputTime())
+    if (time_.writeTime())
     {
         const fvMesh& mesh =
             time_.lookupObject<fvMesh>(polyMesh::defaultRegion);