feature: show a red dot on the minimap whenever a cell gets set

it is hidden again after 300ms. The flash shows whether you set the cell yourself, or if it is set by another
bugfix: the url hash should set the location of the center of the view, not the origin

This way it will show the same thing, no matter the users screen size
clicking on the minimap moves to that location
show the setcell flashes even if they are off the edge of the map

(but only up to some certain preset distance)
when starting with no saved location, do not just load the origin, pick something from a list of presets

The origin is so crowded, its better to have some other locations that the user can start at with more space to work