0024257: Minor corrections for building / testing on VC++ 11

Several corrections coming from building and testing on MSVC++ 11:
- compiler warnings corrected in structiges.c (32-bit mode) and BOPAlgo (64-bit mode)
- DRAW command for testing exceptions (OCC6143) refactored for getting some output even if process fails (problem with stack overflow handling)
- DRAW command readstep removed as it leads to hang-up in Debug mode due to waiting for user input; the only test that used it changed to use testreadstep command

src/BOPAlgo/BOPAlgo_Builder_2.cxx

@@ -96,9 +96,9 @@ void BOPAlgo_Builder::FillImagesFaces()
 void BOPAlgo_Builder::BuildSplitFaces()
 {
   Standard_Boolean bHasFaceInfo, bIsClosed, bIsDegenerated, bToReverse;
-  Standard_Integer i, j, aNbS, aNbPBIn, aNbPBOn, aNbPBSc, aNbAV, nSp;
+  Standard_Integer i, j, k, aNbS, aNbPBIn, aNbPBOn, aNbPBSc, aNbAV, nSp;
   Standard_Boolean bRunParallel;
-  Standard_Size aNbBF, k;
+  Standard_Size aNbBF;
   TopoDS_Face aFF, aFSD;
   TopoDS_Edge aSp, aEE;
   TopAbs_Orientation anOriF, anOriE;
@@ -267,7 +267,7 @@ void BOPAlgo_Builder::BuildSplitFaces()
   BOPAlgo_BuilderFaceCnt::Perform(bRunParallel, aVBF);
   //===================================================
   //
-  for (k=0; k<aNbBF; ++k) {
+  for (k=0; k<(Standard_Integer)aNbBF; ++k) {
     aLFIm.Clear();
     //
     BOPAlgo_BuilderFace& aBF=aVBF(k);

src/BOPAlgo/BOPAlgo_Builder_2Cnt.hxx

@@ -63,7 +63,7 @@ class BOPAlgo_BuilderFaceFunctor {
     iBeg=aBR.begin();
     iEnd=aBR.end();
     for(i=iBeg; i!=iEnd; ++i) {
-      BOPAlgo_BuilderFace& aBF=aVBF(i);
+      BOPAlgo_BuilderFace& aBF=aVBF((Standard_Integer)i);
       //
       aBF.Perform();
     }