fixes #0001422: Subclass Exception

inherit Base.FreeCADError form RuntimeError
inherit Part.OCCError from Base.FreeCADError
inherit OCCDomainError from Part.OCCError
inherit OCCRangeError from Part.OCCError
inherit OCCConstructionError from OCCDomainError
inherit OCCDimensionError from OCCDomainError
Added PY_CATCH_OCC macro
replace PyExc_Exception
use FreeCADError in makeWireString
catch exception in BSplineCurve.increasedegree

src/Main/FreeCADGuiPy.cpp

@@ -182,7 +182,7 @@ FreeCADGui_embedToWindow(PyObject * /*self*/, PyObject *args)
 
     QWidget* widget = Gui::getMainWindow();
     if (!widget) {
-        PyErr_SetString(PyExc_Exception, "No main window");
+        PyErr_SetString(Base::BaseExceptionFreeCADError, "No main window");
         return 0;
     }