Display a direction indicator and allow easy entry of direction values

[simonpoole]

Currently this supports direction, camera:direction and lamp:direction direction entering support for nodes via the property editor and magnetic compass, and new, additionally to ways, support for rotating vie dragging for both individual nodes, multiple elements and multi-polygons.

Resolves #2364

Resolves #1682

Resolves #1157

[goldfndr]

s/arroe/arrow/ (Rotating elements help)
[Possibly also s/WS84/WGS84/]

[jajajaneeneenee]

Both the new direction input option with compass and the arrow display are great!

I noticed a small cosmetic problem in the property editor: If an item contains a direction key with a combo (maybe editable) that contains e.g. display_values="Forward,Backward, ..." then the display_values ​​are no longer taken into account for the display in the property editor - e.g. "forward" and "backward" are now displayed in lowercase (which is somewhat irritating) – I mean after the value was assigned. (As long as the input option with compass is displayed, the display_values are shown.)

I had this case on a node with a traffic_sign=* tag and a custom preset of mine (direction can be forward/backward for nodes on ways – probably the most common case – or a cardinal direction for nodes beside ways).

[simonpoole]

Please open a new issue for new issues, we can't track them in an already closed one.