Display option: Show All Schedules' Stops

[Isaac Eiland-Hall]

Description: An option to toggle the display of all stops from all schedules/lines.

Explanation: When creating/editing a line or schedule, included stops are highlighted in red. It would be handy to be able to toggle that highlighting for all lines/schedules.

In one case, if you have a large stop, you might not remember which is the primary tile (i.e. using choose signs).

Another might be if you have a large stop and need to redesign it, it can help you be sure you're not removing a stop tile with a current line.

And finally, it can make sure you haven't placed any stops that you forgot to serve with at least one line.