0024129: Eliminate remaining compiler warnings in MSVC++ 2008 32 bit with warning level 4

List of resolved warnings:

c4063: Aspect.cdl; TObj_Application.cxx; PCDM.cdl; OpenGl_Workspace_5.cxx;
c4100: XDEDRAW.cxx; ViewerTest_ViewerCommands.cxx; TopOpeBRep_FacesFiller_1.cxx; TopClass_Classifier3d.gxx; TDataStd_ReferenceArray.cxx; QABugs_19.cxx; IntPatch_ImpImpIntersection_5.gxx; HLRTopoBRep_DSFiller.cxx; HLRBRep_Data.lxx; DPrsStd_AISPresentationCommands.cxx; BRepMesh_Delaun.cxx;
c4127: BOPTools_AlgoTools2D.cxx; MAT_Mat.gxx; GeomFill_SweepSectionGenerator.cxx; BRepMesh_Delaun.cxx;
c4189: IntCurveSurface_Inter.gxx; IGESToBRep_BRepEntity.cxx; BRepMesh_Delaun.cxx; BRepAlgo_Loop.cxx; IntStart_SearchOnBoundaries_1.gxx;
c4190: Plugin_Macro.hxx;
c4389: Visual3d_View.cxx; TopOpeBRep/TopOpeBRep_vpr.cxx; TDataStd_BooleanArray.cxx; IntPatch_ALine.cxx;
c4701: BRepAlgo.cxx;
c4702: MNaming_NamingRetrievalDriver_1.cxx; MNaming_NamingRetrievalDriver_2.cxx; BRepClass3d_SolidExplorer.cxx;
c4706: TestTopOpe_BOOP.cxx;

Additional fixes:
- old-style declarations of C functions in IGES and STEP parsers
- clean-up of debug code, fixes for building in Debug mode
- in BRepFill_TrimShellCorner.cxx, lines 878-9, wrong use of assignment instead of comparison fixed
- fix for Plugin_Macro reverted; warning 4190 disabled instead
- in IntPatch_ALine.cxx, line 520, wrong comparison of boolean with index fixed
- in InterfaceGraphic_Visual3d.hxx, field IsCustomMatrix made boolean
- in TopOpeBRepBuild_ShapeSet, obsolete (unused) methods removed

src/XmlDrivers/XmlDrivers.cxx

@@ -38,11 +38,6 @@
 
 #include <Plugin_Macro.hxx>
 
-// avoid warnings on 'extern "C"' functions returning C++ classes
-#ifdef WNT
-#pragma warning(4:4190)
-#endif
-
 static Standard_GUID XmlStorageDriver  ("03a56820-8269-11d5-aab2-0050044b1af1");
 static Standard_GUID XmlRetrievalDriver("03a56822-8269-11d5-aab2-0050044b1af1");
 
@@ -93,5 +88,9 @@ Handle(XmlMDF_ADriverTable) XmlDrivers::AttributeDrivers
   return aTable;
 }
 
+#ifdef _MSC_VER
+#pragma warning(disable:4190) /* disable warning on C++ type returned by C function; should be OK for C++ usage */
+#endif
+
 // Declare entry point PLUGINFACTORY
 PLUGIN(XmlDrivers)