0022972: Eliminate macro definitions that has compiler-provided analogs (WNT and so on)

1) Macro definition WNT replaced by _WIN32 and _MSC_VER for platform and compiler detection accordingly.
2) Macro definition LIN replaced by __linux__ macro.
3) Macro definition DEB replaced by OCCT_DEBUG macro.

src/math/math_FunctionRoots.cxx

@@ -27,8 +27,6 @@
 #include <TColStd_Array1OfReal.hxx>
 
 #include <stdio.h>
-//#ifdef WNT
-//#endif
 #define ITMAX  100
 #define EPS    1e-14
 #define EPSEPS 2e-14

src/math/math_Recipes.hxx

@@ -20,7 +20,7 @@
 #include <Standard_Real.hxx>
 
 #ifndef __math_API
-# if defined(WNT) && !defined(HAVE_NO_DLL)
+# if defined(_WIN32) && !defined(HAVE_NO_DLL)
 #  ifdef __math_DLL
 #   define __math_API __declspec( dllexport )
 #  else
@@ -28,7 +28,7 @@
 #  endif  /* __math_DLL */
 # else
 #  define __math_API
-# endif  /* WNT */
+# endif  /* _WIN32 */
 #endif  /* __math_API */
 
 class math_IntegerVector;