Epic board lists: parent-child view & movement

This is an issue to discuss possible improvements.

Right now a user doesn't see the parent-child relationships on epic board lists. There are multiple issues with that

• users don't know about the relationships
• right now users can move any epic, no matter which list its parent/children are on
  • should we allow that or should we allow only moving parent with its children?
• right now we count number of epics in a list (and issues weight sum) based on epics that are really in a list. When we have epic A in a list A and its Subepic B in list B, the Subepic B is not counted in List A
  • should we allow this status (previous question)
  • if we do, how should we count epics count & weights?