unify routing of event#show as "%Y-%m-%d"
turn off error page without production
add event participants data and its edit page

- add EventParticipant model.
- add Event#edit and Event#update action.
add event participants data and its edit page

- add EventParticipant model.
- add Event#edit and Event#update action.
create :check_logined to use before action
change title of the site
add mail address of the administrator to the menu
add player's page