Show a better error message if trying to play a quest with format 0.9
Created by: christopho
When running Solarus 1.0 or 1.1 with a quest that works for Solarus 0.9, the error message is not very helpful.
Created by: christopho
When running Solarus 1.0 or 1.1 with a quest that works for Solarus 0.9, the error message is not very helpful.