add few rules for one call function (routes function), class View

[fanatid]

it's attempt make routes more easy and add class based views

• change route function
• rename add_url_rule to add_route
• change kwarg options to defaults
• change url_for function
• add class View in views.py -- this allow make common views (see test_plugin.TestBasicRouting.test_class_views for example)

[fanatid]

I think is no need reason include this pull request. Class and routes may use like this:

class BaseView(object):
    def view(self, *args, **kwargs):
        raise NotImplementedError

class View1(BaseView):
    def view(self):
        code1

class View2(BaseView):
    def view(self):
        code2

routes = (
    ('/view1', View1().view, 'view1'),
    ('/view2', View1().view, 'view2'),
)
for route in routes:
    plugin.add_url_rule(*route)

[dersphere]

Even when there is no code change needed, I am quite sure @jbeluch would happily accept an PR to the docs where you describe this pattern in detail.
At least I would do ;)