0025418: Debug output to be limited to OCC development environment

Macros ending on "DEB" are replaced by OCCT_DEBUG across OCCT code; new macros described in documentation.
Macros starting with DEB are changed to start with "OCCT_DEBUG_".
Some code cleaned.

src/XCAFDoc/XCAFDoc_ShapeTool.cxx

@@ -146,7 +146,7 @@ static void SetLabelNameByLink(const TDF_Label L)
   Handle(TDataStd_TreeNode) Node;
   if (! L.FindAttribute(XCAFDoc::ShapeRefGUID(), Node) ||
       ! Node->HasFather()) {
-#ifdef XCAFDOC_DEB
+#ifdef OCCT_DEBUG
     cout<<"Error: XCAFDoc_ShapeTool, SetLabelNameByLink(): NO NODE"<<endl;
 #endif
     return;