0024023: Revamp the OCCT Handle - gcc and clang

Adaptations for compiling with GCC 4.7 and 4.8:
- Construction semantics is used for Handle objects being initialized by const Handle objects of derived type, to avoid overload resolution error in GCC 4.7.
- Missing includes added.
- Fixed bugs related to misuse of direct casts of handle.
- Eliminate CLang warnings on uninitialized and unused variables, functions, and expressions

src/CSLib/CSLib_Offset.cxx

@@ -16,11 +16,6 @@
 #include <gp_Dir2d.hxx>
 #include <gp_XY.hxx>
 
-#include <Geom_UndefinedValue.hxx>
-#include <Geom_UndefinedDerivative.hxx>
-#include <Geom2d_UndefinedValue.hxx>
-#include <Geom2d_UndefinedDerivative.hxx>
-
 #include <Standard_NullValue.hxx>