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
removed catch (...) in Drawing

which discarded type information when rethrowing base type
issue #1700 replace PyExc_Exception