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/PLib/FILES

@@ -11,4 +11,4 @@ PLib_HermitJacobi.lxx
 PLib_JacobiPolynomial.cxx
 PLib_JacobiPolynomial.hxx
 PLib_JacobiPolynomial.lxx
-PLib_JacobiPolynomial_0.hxx
+PLib_JacobiPolynomial_Data.pxx

src/PLib/PLib_JacobiPolynomial.cxx

@@ -17,13 +17,14 @@
 #include <math_Vector.hxx>
 #include <PLib.hxx>
 #include <PLib_JacobiPolynomial.hxx>
-#include <PLib_JacobiPolynomial_0.hxx>
 #include <Standard_ConstructionError.hxx>
 #include <Standard_Type.hxx>
 #include <TColStd_Array2OfReal.hxx>
 
 IMPLEMENT_STANDARD_RTTIEXT(PLib_JacobiPolynomial,PLib_Base)
 
+#include "PLib_JacobiPolynomial_Data.pxx"
+
 // The possible values for NbGaussPoints
 const Standard_Integer NDEG8=8,   NDEG10=10, NDEG15=15, NDEG20=20, NDEG25=25, 
                        NDEG30=30, NDEG40=40, NDEG50=50, NDEG61=61;

src/PLib/PLib_JacobiPolynomial_Data.pxx

@@ -16850,5 +16850,3 @@ static const Standard_Real MaxValuesDB_C2[53] = {
   2.68923766976735295746679957665724,
   2.71238965987606292679677228666411
 };
-
-//#include <PLib_JacobiPolynomial_1.cxx>