Create a screen/report that shows all the current key mappings.

[RHolton]

Widelands is getting more and more possibilities for assigning functions to keys. It would be helpful to have a screen where all of the current key mappings are displayed.

Ideally, the user could pick to view the key mappings organized by function or by key order (alphabetical, with the various shift/ctrl/alt combinations).

This would be useful in the configuration menus, helping to find which keys are available (think Fastplace). It would also be helpful in-game, to remind the user how to use keys to accomplish different tasks.

I suppose there might need to be different reports for different contexts, but I think the main focus should be the in-game key mappings.