only allow to specify availability on registration form if player has not been accepted for the season already (as then they can and should use "edit availability" instead of changing their registration.
Help text in the registration forms extended to make more clear that players need to get an established rating before registrations are processed. The helptext in lonewolf registrations mentions exceptions that might apply for lonewolf.
fixes #409 fixes #447 fixes #468
only allow to specify availability on registration form if player has not been accepted for the season already (as then they can and should use "edit availability" instead of changing their registration.
Help text in the registration forms extended to make more clear that players need to get an established rating before registrations are processed. The helptext in lonewolf registrations mentions exceptions that might apply for lonewolf.