* Replace all ctx.Handle with ctx.ServerError or ctx.NotFound

* Change Handle(403) to NotFound, avoid using macaron's NotFound

* Integration test for activity page

* Small code refactoring for acitvity page

* Move activity stats calculation logic to model

* Add Activity page to repository

* Add request data for activity

* Add issue data for activity

* Add user unit right checks

* Add releases to activity

* Log repository unit loading error