[FEATURE] linking issue references

Created by: YenZi

Is there any way to group issues ? In redmine e.g. you have the possibility to reference subtasks. So, what I am looking for is some kind of back reference. Let's say in issue # 400 you enter "references # 405 # 507 # 654". Then it would be great if issue # 405 would automatically display a reference to the "super issue" # 400. Same for # 507 and # 654 of course.