GeoInterface cleanup needed

[rafaqz]

I noticed a bunch of weird stuff in the geo_interface.jl file during other PRs, like: https://github.com/JuliaGeo/LibGEOS.jl/blob/1c12df5f0677f2efd1def7b4ecb8ebd9bcaad40f/src/geo_interface.jl#L59 https://github.com/JuliaGeo/LibGEOS.jl/blob/1c12df5f0677f2efd1def7b4ecb8ebd9bcaad40f/src/geo_interface.jl#L49 https://github.com/JuliaGeo/LibGEOS.jl/blob/1c12df5f0677f2efd1def7b4ecb8ebd9bcaad40f/src/geo_interface.jl#L62

It could also do with some organization and comments

[evetion]

Agreed. The zero seems like a wrong copy. The other two might be required for Aqua? Good to test though.

[rafaqz]

I wondered that too, they at least need "ambiguity" comments if so