ptot: Add support for -region

Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=1227
Patch provided by Bruno Santos

applications/utilities/postProcessing/miscellaneous/ptot/ptot.C

@@ -36,13 +36,14 @@ Description
 int main(int argc, char *argv[])
 {
     timeSelector::addOptions();
+    #include "addRegionOption.H"
 
     #include "setRootCase.H"
     #include "createTime.H"
 
     instantList timeDirs = timeSelector::select0(runTime, args);
 
-    #include "createMesh.H"
+    #include "createNamedMesh.H"
 
     forAll(timeDirs, timeI)
     {