Layer - add method to get parent dataset

[shawnlaffan]

What do you think of adding a method to get at a layer's parent dataset?

It is not part of the GDAL API so far as I can see, but since Geo::GDAL::FFI stores a hash of parent refs it should be possible to access it and return the relevant item.

This would be convenient when passing layers between subs to use for selections, as one does not need to also pass the dataset ref.

Something like this might be sufficient:

sub GetParentDataset {
    my ($self) = @_;
    return $Geo::GDAL::FFI::parent ($$self);
}

[ajolma]

I think it is useful.

[shawnlaffan]

Thanks. I'll work it into a PR.

[shawnlaffan]

Fixed by PR #24