#2 support for decorators

[ill-665]

Python supports a decorator notation since at least version 2.5.
With this feature, Python allows to create static methods in the following ways:

class TestClass (object):
@staticmethod
def foo ():
....

@classmethod
def bar (cls):
....

Maybe there can be included a settings option, that allows to tell PyUML, which way to use for static method definitions.