[dev] Feature-request: specific error-message if ACL denies action

Hi, as far as I can see, very specific designed ACLs can be used to design a workflow, e.g. ticket may only be locked (to work on it) if the default priority "undefined" was changed to a specific value before If a ACL is not true, a simple error-message "access denied" is displayed as far as I can remember. It could be useful if a message can be defined on every ACL to be displayed if the ACL is not true, e.g. You have to specify Priority before working on the ticket. Bye, Alex