Fixes

https://www.pivotaltracker.com/story/show/70365092
https://www.pivotaltracker.com/story/show/70634380
https://www.pivotaltracker.com/story/show/69100114

- Fixed the Flash Partial which was showing alert messages for Notice Flash
- Added `authenticate_user!` before actions that shouldn't be accessed by unauthenticated users
- Added `utf8-cleaner` gem so that 500 Internal Server Error wouldn't be caused when there are UTF-8 chars in the url.