handle error when looking for a tournament that doesn't exist

Name: RobotTournament-jf.20
Author: jf
Time: 20 January 2013, 3:30:02 pm
UUID: b9674f1f-9645-4c16-91a5-0a149d2267cf
Ancestors: RobotTournament-jf.19
Allow creating and editing of tournaments with HTML forms

Name: RobotTournament-jf.21
Author: jf
Time: 20 January 2013, 10:38:57 pm
UUID: e6037244-380b-444c-88d2-fa1ad499e698
Ancestors: RobotTournament-jf.20