Map legend position to layers

[BalzGuenat]

No description provided.

[ruiqimao]

Could we get the help icons to line up on the right? Also figure out a way to get the button centered, since it looks kind of awkward off to the side. And the text in the textboxes centered.

We probably also want these settings saved in the json, which means the serialize() and deserialize() functions need to be changed while maintaining compatibility with older json files.

And one more thing, can we get all the functions fully documented? There are a few that don't have docstrings above them.

Other than that, looks like it works. Good job!

[BalzGuenat]

Thanks for the comments. I implemented your suggestions. (De-)Serialization code did not have to be changed.