Widgets can't act as Controllers

tw2 widgets should be able to act as controllers
(http://tw2core.readthedocs.org/en/latest/design/#widgets-as-controllers). A
bug in tw2.core.middleware.ControllersApp does not allow to detect controller
prefix in path. Registered controllers are unreachable (http error 404).

I suspect this bug was not relevant until controller_prefix changed to '/tw2/controllers/' TurboGears/tg2@3fa1679

This patch will fix problem. It's ugly but it just works for me.

--- tw2/core/middleware.py
+++ tw2/core/middleware.py
@@ -257,6 +257,7 @@
     def __call__(self, req):
         config = rl = core.request_local()['middleware'].config
         path = req.path_info.split('/')[1:]
+        path = ['/'.join(path[:-1]), path[-1]]
         pre = config.controller_prefix.strip('/')
         if pre and path[0] != pre:
             return wo.Response(status="404 Not Found")