Add alternative names for cursor icons

[Friz64]

Many cursor themes in the wild don't adhere to the w3c standard, and only use legacy names.

The list in this PR is from a list in an older version of winit, keeping only the names that don't match the standard.

Also see: Smithay/client-toolkit#425

cc @kchibisov

[kchibisov]

Could you check what Qt and GTK are using as well?

[Friz64]

Could you check what Qt and GTK are using as well?

Good call. Qt especially had a lot of alternatives.

How close should we stay to the original cursor? Let's for example look at CursorIcon::Copy, which is described as "Indicates something is to be copied. Often rendered as an arrow with a small plus sign next to it.". My cursor theme does not have that exact icon, but it does have a drag&drop variant of it (referred to as dnd-copy) where instead of the arrow, there is a dragging hand. Should this be listed or should we stay as close to the original as possible? My current version opts to not list it.

[kchibisov]

How close should we stay to the original cursor? Let's for example look at CursorIcon::Copy, which is described as "Indicates something is to be copied. Often rendered as an arrow with a small plus sign next to it.". My cursor theme does not have that exact icon, but it does have a drag&drop variant of it (referred to as dnd-copy) where instead of the arrow, there is a dragging hand. Should this be listed or should we stay as close to the original as possible? My current version opts to not list it.

No, if it doesn't have it then it doesn't have it.

[kchibisov]

Thanks.