#1 Pin doesn't disappear when clicking on pan-bar

[Peter Segerstedt]

When adding a new Herman dough, the user is to click in
the map in order to "pin" the geographical location of the
dough. If the user then clicks on one of the pan-arrows,
the pin stays in the same place relative to the map-
image extent which is wrong since it should reflect the
location "on-the-earth".

Proposed solution: Either make it disappear so that the
user has to re-pin OR calculate and move the pin
accoring to the new map-view.