Allow placement of the same marker multiple times

[DavidnCothron]

I.E., When placing down a blue mortar marking, and then placing down a blue fire mission marker, allow placing multiple of a marker with an auto-incrementing numeric ID. This would work by showing no number if only one of a marker exists, and then showing a small "1" on the first marker and a small "2" on the second marker placed, on so on.

This would allow mocking up a more real-use case map where the color of the markers indicates teams, squads, order of targets, etc,. You could, for example, use blue or green markers for one team, placing multiple HAB markers or mortar markers and use red for the opposing team.

[Endebert]

Sounds quite complicated, but if anyone manages to implement it, I'll gladly integrate it, as I have nothing against it per se.