This fix still allows depending on attributes of a Parameterized that are themselves Parameterized but are not declared as a parameter. Since some people are relying on this I did not want to remove that behavior. The actual bug that caused #635 was that if you depended on an attribute that was Parameterized it would treat it as if it was an undecorated method declaration, which are treated as if they depend on all parameters, i.e.:

class Sub(param.Parameterized):
    s = param.String()

class P(param.Parameterized):
    test_param = param.Parameter()

    def __init__(self, **params):
        self._sub = Sub()
        super().__init__(**params)

    @param.depends('_sub.s', watch=True)
    def cb(self):
        print('cb called')

was functionality treated very similarly to this:

class P(param.Parameterized):
    test_param = param.Parameter()

    def test(self):
        pass

    @param.depends('test', watch=True)
    def cb(self):
        print('cb called')

and since test does not declare dependencies that means cb will end up watching name and test_param.

Fixes #635