0023934: Compiler warnings in MS VC++ 10

Elimination of compiler warnings
- ExprIntrp: generated file ExprIntrp.tab.c and related WOK scripts removed from the sources
- ExprIntrp, StepFile: added missing declarations and casts; warnings caused by Flex and Bison code suppressed for MSVC compuler by #pragma
- OSD: dummy #includes added to files containing no code for Windows, to avoid warning on empty file
- PLib: piece of code contained in PLib_ChangeDim.gxx included explicitly in cxx and cleaned
- Other places: some casts added to avoid warnings

src/StepFile/step.lex

@@ -45,6 +45,11 @@ void rec_typarg(int argtype);
   void resultat ()           /* Resultat alloue dynamiquement, "jete" une fois lu */
       { if (modcom == 0) rec_restext(yytext,yyleng); }
 
+// disable MSVC warnings in flex code
+#ifdef _MSC_VER
+#pragma warning(disable:4131 4244 4273 4267 4127)
+#endif
+
 %}
 %%
 "	"	{;}