ENH: use unique_ptr for resource handling in dynamicMesh

ENH: defaulting for destructors where possible

STYLE: clear() instead of setSize(0) for plain Lists

STYLE: use bool operator instead of valid()/empty() for autoPtr tests

src/dynamicMesh/meshCut/meshModifiers/meshCutter/meshCutter.C

@@ -516,12 +516,6 @@ Foam::meshCutter::meshCutter(const polyMesh& mesh)
 {}
 
 
-// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
-
-Foam::meshCutter::~meshCutter()
-{}
-
-
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
 void Foam::meshCutter::setRefinement