ENH: provide Time::NewGlobalTime factory methods (#3007)

- avoids clutter of argList::envGlobalPath() ...

ENH: allow temporary overwriting of output writeFormat

- allows switching for particular output routines

COMP: explicitly use TimePaths methods with Time

- this simplifies any overloading done at a later stage

src/parallel/reconstruct/faReconstruct/faMeshReconstructor.C

@@ -454,7 +454,7 @@ void Foam::faMeshReconstructor::createMesh()
     const Time& runTime = procMesh_.thisDb().time();
 
     // Time for non-parallel case (w/o functionObjects or libs)
-    serialRunTime_ = Time::New(runTime.globalPath().toAbsolute());
+    serialRunTime_ = Time::NewGlobalTime(runTime);
 
 
     // Trivial polyMesh only containing points and faces.