Artwork: SVG for map markers

Signed-off-by: mvglasow <michael -at- vonglasow.com>
Commented out attempt at styling map reattach button

Signed-off-by: mvglasow <michael -at- vonglasow.com>
Show marker in map (still experimental)

Marker is currently in one color (like circles) and always shown, even when
the circle is visible

Signed-off-by: mvglasow <michael -at- vonglasow.com>
Add map markers in all colors, make map overlays stylable

Signed-off-by: mvglasow <michael -at- vonglasow.com>