Quick success on permission calculation from allow overwrites

[swarley]

Closes #700

End calculation early when an allow override is met

---

Fixed

PermissionCalculator#defined_role_permission?

[GrapeColor]

What about setting the overwrited flag so that if there is a channel overwrite, that one has priority?

overwrited = false  # add
roles_to_check.sort_by(&:position).reduce(false) do |can_act, role|
  # Get the override defined for the role on the channel
  channel_allow = permission_overwrite(action, channel, role.id)

  # If the channel has an override, check whether it is an allow - if yes,
  # the user can act, if not, it can't
  if channel_allow
    overwrited = true  # add
    return true if channel_allow == :allow

    false
  else
    # Otherwise defer to the role
    !overwrited && role.permissions.instance_variable_get("@#{action}") || can_act  # add
  end
end

[Daniel-Worrall]

This was merged via shardlab/discordrb@9cc3a26 in the new repo and released in v3.4.0 and can be closed.