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/BRepOffsetAPI/BRepOffsetAPI_MakeOffset.cxx

@@ -335,7 +335,7 @@ void BRepOffsetAPI_MakeOffset::Perform(const Standard_Real Offset,
   }
   catch(...) //Every exception was caught.
   {
-#ifdef BREPOFFSETAPI_DEB
+#ifdef OCCT_DEBUG
     cout<<"An exception was caught in BRepOffsetAPI_MakeOffset::Perform : ";
     Standard_ConstructionError::Caught()->Print(cout); 
     cout<<endl;