0028417: Using PRECOMPILED HEADER to speed up compilation time

Use of Cotire tool is introduced for acceleration of CMake builds, by usage of precompiled headers.
CMake option BUILD_USE_PCH is added to enable / disable use of precompiled headers

When precompiled headers are used, additional compiler macros are defined globally in the build system to avoid problems due to different order of included files:
- NOMINMAX is defined on Windows to prevent defining "min" and "max" as macros by windows.h
- STRSAFE_NO_DEPRECATE and _SCL_SECURE_NO_WARNINGS are defined on Windows to prevent declaring functions of standard C library as deprecated by #pragma, and other warnings in system headers
- GL_GLEXT_LEGACY and GLX_GLEXT_LEGACY are defined to ensure that only OCCT's own glext.h is used
- __STDC_FORMAT_MACROS is defined to have standard C print format macros always defined

Code is corrected to avoid conflicts with system headers and in case of compiling together as unity builds (partially):
- Some locally defined variables in TKV3d, TKHLR are renamed to be unique
- Duplicated definitions of macros and global functions are eliminated in TKSTEP
- Useless header WNT_UInt.hxx is removed
- Usage of local variables conflicting with X11 macro is avoided in Draw_Viewer.cxx
- Local variables in AIS_ConcentricRelation.cxx are renamed to avoid conflict with macros defined in windows.h
- HXX files containing code are renamed to PXX or merged with corresponding CXX files.

IVtkTools classes are corrected to avoid compiler warnings disabled in non-PCH builds by inclusion of VTK headers.

Useless pragmas disabling warnings on MSVC are removed

src/IVtkTools/IVtkTools_ShapeDataSource.hxx

@@ -24,6 +24,11 @@
 class vtkIdTypeArray;
 class vtkPolyData;
 
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable: 4251) // avoid warning C4251: "class needs to have dll-interface..."
+#endif
+
 //! @class IVtkTools_ShapeDataSource.
 //! @brief VTK data source for OCC shapes polygonal data.
 class IVtkTools_EXPORT IVtkTools_ShapeDataSource : public vtkPolyDataAlgorithm
@@ -113,4 +118,8 @@ protected:
 
 };
 
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
 #endif // __IVTKTOOLS_SHAPEDATA_H__