Input of dimensionedScalars: update read-construction of dimensionedScalar in applications

so that the specification of the name and dimensions are optional in property dictionaries.

Update tutorials so that the name of the dimensionedScalar property is
no longer duplicated but optional dimensions are still provided and are
checked on read.

applications/solvers/incompressible/boundaryFoam/createFields.H

@@ -1,49 +1,49 @@
-    Info<< "Reading field U\n" << endl;
-    volVectorField U
+Info<< "Reading field U\n" << endl;
+volVectorField U
+(
+    IOobject
     (
-        IOobject
-        (
-            "U",
-            runTime.timeName(),
-            mesh,
-            IOobject::MUST_READ,
-            IOobject::AUTO_WRITE
-        ),
-        mesh
-    );
-
-
-    Info<< "Creating face flux\n" << endl;
-    surfaceScalarField phi
-    (
-        IOobject
-        (
-            "phi",
-            runTime.timeName(),
-            mesh,
-            IOobject::NO_READ,
-            IOobject::NO_WRITE
-        ),
+        "U",
+        runTime.timeName(),
         mesh,
-        dimensionedScalar("zero", mesh.Sf().dimensions()*U.dimensions(), 0.0)
-    );
+        IOobject::MUST_READ,
+        IOobject::AUTO_WRITE
+    ),
+    mesh
+);
 
 
-    singlePhaseTransportModel laminarTransport(U, phi);
-
-    autoPtr<incompressible::RASModel> turbulence
+Info<< "Creating face flux\n" << endl;
+surfaceScalarField phi
+(
+    IOobject
     (
-        incompressible::RASModel::New(U, phi, laminarTransport)
-    );
+        "phi",
+        runTime.timeName(),
+        mesh,
+        IOobject::NO_READ,
+        IOobject::NO_WRITE
+    ),
+    mesh,
+    dimensionedScalar("zero", mesh.Sf().dimensions()*U.dimensions(), 0.0)
+);
 
-    dimensionedVector Ubar(laminarTransport.lookup("Ubar"));
 
-    vector flowDirection = (Ubar/mag(Ubar)).value();
-    tensor flowMask = sqr(flowDirection);
+singlePhaseTransportModel laminarTransport(U, phi);
 
-    dimensionedVector gradP
-    (
-        "gradP",
-        dimensionSet(0, 1, -2, 0, 0),
-        vector::zero
-    );
+autoPtr<incompressible::RASModel> turbulence
+(
+    incompressible::RASModel::New(U, phi, laminarTransport)
+);
+
+dimensionedVector Ubar("Ubar", dimVelocity, laminarTransport.lookup("Ubar"));
+
+vector flowDirection = (Ubar/mag(Ubar)).value();
+tensor flowMask = sqr(flowDirection);
+
+dimensionedVector gradP
+(
+    "gradP",
+    dimensionSet(0, 1, -2, 0, 0),
+    vector::zero
+);