[jlqjcgxi] Out of order UI

Create a generic UI for interacting with linear data arriving out of order (perhaps due to network).

A system with sequence numbers gives a hint that data are missing.  Or a system without, using only timestamps, gives no indication until the out of order data arrives.

Easy (too easy) is to delay showing data until we are sure the data are in order.  Instead, we want to display (and allow other interaction) data as it arrives (not freezing for a missing item) and indicate when and where a reordering occurs.

Inspired by text messages.