Bug fixes for the editor tools item detail window:
- updated editor activity so that reference to a displayed item detail window is retained across activity lifecycle events. Before that update, dismissing an item detail window after a lifecycle event (i.e: orientation switch) would leave the mission item in a selected state (instead of deselecting it), among other possible issues.

- updated the mission detail fragment to notify its listener/parent when it's being dismissed, when shown as a dialog.