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/Base/PyObjectBase.cpp

@@ -33,6 +33,8 @@
 
 using namespace Base;
 
+PyObject* Base::BaseExceptionFreeCADError = 0;
+
 // Constructor
 PyObjectBase::PyObjectBase(void* p,PyTypeObject *T)
   : _pcTwinPointer(p), parent(0), attribute(0)