"Add dataset to organization" should auto-select the organization

[seanh]

'Add dataset to organization' button, when you get through to the third stage of the new dataset form the organization you came from is not selected.

I don't see any option to choose the group when adding or updating a dataset, but if I add a dataset via the "Add dataset to group" button on a group's page, then the dataset seems to get added to that group. (And I can also add/remove existing datasets by editing the group.) I wonder if organizations should work the same way, instead of having an Organization drop-down when creating or updating a dataset. The add dataset page needs to somehow indicate that you're adding a dataset to a certain group or organization though, doesn't currently.