change the direction of the new way when combining with a coastline

[dieterdreist]

If you draw a new way and combine it with a coastline way, and they don't go in the same direction, the direction of the existing coastline should be the result, not the one of the newly drawn way.

[skyper]

Direction should always be the one of the existing way!

This is also important for barrier=retaining_wall and waterway=riverbank

[dieterdreist]

Replying to skyper:

Direction should always be the one of the existing way!

This is also important for barrier=retaining_wall and waterway=riverbank

Yes, it is important for some barriers (cliffs as well), for most waterways (riverbank shouldn't matter, at least according to the wiki), for steps, for ways with direction-dependent tags like forward or backward, left and right, ...

[stoecker]

In 8181/josm:

fix #5880 - reverse new ways in favour of existing ones

[stoecker]

In 8182/josm:

see #5880 - copy and paste error