utils/server: Add inspect ability to cli_server

The ``application`` argument is now optional; if passed ``None`` the
function will then try to extract one from ``locals()`` of the caller's
frame.

This saves some keystrokes for webapp writers :D
Add convenient shortcuts

* automatic instantiation of ``ReflexResponse``
* alias of ``weiyu.rendering.decorators.renderable``
* shortcut of ``@router_hub.endpoint('http', 'something')``
* the ``init_router_from_config`` and ``register_router`` combo
update examples and included views to use shortcuts
Merge branch 'shortcuts'