Use exact map places and animations from event attributes

Event attributes can now give the Map more precise instructions.

• Choose an exact place: copy a Map ID from a place-package search result and use it as the event's mapid. Historic places with several versions can use the boundary that fits each event's date.
• Set how it arrives: mapanim can make the place move or change shape, draw a line, fade in or drop in.
• End a mapped story: mapend=yes makes that atlas's places fade out at the event, without linking later places across the ending.
• Copy a complete historic set: Copy all collects the available versions so they can be used when preparing imported events.
• Missing package notices: if a project uses a Map ID whose place package is not on the device, the Map tells you which package is needed.