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/functionObjects/utilities/areaWrite/areaWrite.H

@@ -38,7 +38,7 @@ Description
         libs    (utilityFunctionObjects);
 
         // Write at same frequency as fields
-        writeControl    outputTime;
+        writeControl    writeTime;
         writeInterval   1;
 
         // Fields to be sampled