It can be difficult to distinguish the new marker
which is added on the map and has to be dragged
when editing a new dive location.
By adding a new grayed-out marker it becomes
possible to gray out all other markers, while
the current marker which is being edited is still
bright red.
Suggested-by: Dietrich Meyer <dietrich@sunnynames.com>
Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
